# Fly by wire / accelerator issues



## feared (Aug 13, 2009)

I've had a search through the forum and can't find any posts about this issue.

The other day I went to leave a car park and started moving but the car didn't respond to the accelerator - it was moving with no errors on the MFD but only at idle. 

I'll get a VCDS scan tomorrow but are there any ideas? Is there a known issue with the accelerator potentiometer or wiring?


----------



## invisiblewave (Sep 22, 2008)

The accelerator is disabled if there's any problem with the ABS (take a look at the ABS controller threads), but I'd expect to see some warnings on the dash.


----------



## feared (Aug 13, 2009)

I've tried finding the measuring blocks for the accelerator pedal postion in VCDS but can't find them. 

Any clues? I've tried Engine I and Engine II.


----------



## PanEuropean (Nov 3, 2001)

Could it be that the accelerator pedal is somehow unplugged from the car? It is entirely an electrical connection, no mechanical connection of any kind. 

Michael


----------



## feared (Aug 13, 2009)

I've checked the pedal, and it seems to be connected. In the engine measuring blocks, there is a "Bin. Bits" section that changed from a 1 to a 0 when the accelerator is pressed.

Any other ideas? My car is off the road and might have to end up with the dealers


----------



## feared (Aug 13, 2009)

VCDS scan:


-------------------------------------------------------------------------------
Address 01: Engine Labels: None
Part No SW: 070 906 016 CM HW: 028 101 073 7
Component: V10 5,0L EDCG000AGMª7001 
Coding: 0000175
Shop #: WSC 00200 210 90001
VCID: 5DB59D47FDA1
7 Faults Found:
18005 - Powertrain Databus: Missing Message from Level Control System (J197) 
P1597 - 000 - - - Intermittent
Freeze Frame:
RPM: 0 /min
Torque: 292.3 Nm
Speed: 3.6 km/h
Load: 0.0 %
Voltage: 9.35 V
Bin. Bits: 00001100
Torque: 292.3 Nm
Torque: 0.0 Nm
18036 - Powertrain Data Bus: Missing Message from Steering Angle Sensor 
P1628 - 001 - Upper Limit Exceeded - Intermittent
Freeze Frame:
RPM: 0 /min
Torque: 292.3 Nm
Speed: 3.6 km/h
Load: 0.0 %
Voltage: 9.27 V
Bin. Bits: 00001100
Bin. Bits: 00000000
(no units): 0.0
18057 - Powertrain Data Bus: Missing Message from ABS Controller 
P1649 - 000 - - - Intermittent
Freeze Frame:
RPM: 0 /min
Torque: 292.3 Nm
Speed: 3.6 km/h
Load: 0.0 %
Voltage: 9.27 V
Bin. Bits: 00001100
Torque: 292.3 Nm
Bin. Bits: 00000000
18062 - Please check DTC Memory of Instrument Cluster 
P1654 - 000 - - - Intermittent
Freeze Frame:
RPM: 0 /min
Torque: 292.3 Nm
Speed: 3.6 km/h
Load: 0.0 %
Voltage: 10.03 V
Bin. Bits: 00001100
Bin. Bits: 00000000
(no units): 0.0
19463 - Camshaft Position Sensor (G40): No Signal 
P3007 - 000 - - 
Freeze Frame:
RPM: 588 /min
Torque: 150.1 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 13.07 V
Bin. Bits: 00001111
Idle Stabilization: 0.0°KW
(no units): 48.0
17026 - Sensor Reference Voltage A: Circuit: Low 
P0642 - 000 - - 
Freeze Frame:
RPM: 588 /min
Torque: 150.1 Nm
Speed: 0.0 km/h
Bin. Bits: 00100000
Bin. Bits: 00100000
Bin. Bits: 00100000
Bin. Bits: 00100000
Bin. Bits: 00100000
16887 - Vehicle Speed Sensor: Signal too High 
P0503 - 000 - - 
Freeze Frame:
RPM: 0 /min
Torque: 292.3 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 7.45 V
Bin. Bits: 00001100
Torque: 292.3 Nm
Torque: 0.0 Nm
Readiness: 0 0 X X X 
-------------------------------------------------------------------------------
Address 02: Auto Trans Labels: None
Part No SW: 09F 927 760 C HW: GS1 9.0 4.1 
Component: AG6 09F 5,0L V10TDI 1901 
Coding: 0000101
Shop #: WSC 00200 210 90001
VCID: 316D11F7D1B9
4 Faults Found:
18271 - Powertrain Data Bus: Missing Message from Steering Angle Sensor 
P1863 - 000 - - - Intermittent
Freeze Frame:
Fault Status: 00110000
Fault Priority: 0
Fault Frequency: 21
Reset counter: 38
Mileage: 163478 km
Time Indication: 0
Freeze Frame:
RPM: 704 /min
RPM: 704 /min
RPM: 0 /min
(no units): 30.0
(no units): 23.0
Temperature: 14.0°C
T.B. Angle: 0.0°
18259 - Powertrain Data Bus: Missing Message from ABS Controller 
P1851 - 000 - - - Intermittent
Freeze Frame:
Fault Status: 00110000
Fault Priority: 0
Fault Frequency: 21
Reset counter: 38
Mileage: 163478 km
Time Indication: 0
16946 - System Voltage: Too Low 
P0562 - 000 - - - Intermittent
Freeze Frame:
Fault Status: 00100000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 32
Mileage: 163606 km
Time Indication: 0
18269 - Throttle Position Sensor (G79): Error Message from ECU 
P1861 - 000 - - 
Freeze Frame:
Fault Status: 01110000
Fault Priority: 0
Fault Frequency: 2
Reset counter: 40
Mileage: 164041 km
Time Indication: 0
-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 3D0-614-517.lbl
Part No: 3D0 614 517 AK
Component: ESP 5.7 allrad H33 0047 
Coding: 0008646
Shop #: WSC 00352 000 00000
VCID: 6BD1C39F3315
2 Faults Found:
01314 - Engine Control Module 
013 - Check DTC Memory
01826 - Sensor for Steering Angle (G85); Supply Voltage Terminal 30 
000 - - 
-------------------------------------------------------------------------------
Address 05: Acc/Start Auth. Labels: 3D0-909-13x-05.lbl
Part No SW: 3D0 909 137 D HW: 5WK 485 08
Component: G1 Kessy 6840 
Revision: 68406418 Serial number: VWZ3Z0E1318800
Coding: 0004328
Shop #: WSC 00200 210 90001
VCID: 285BFC93E263
Part No: XXXXXXXXXXX 
Component: ELV XXXX
6 Faults Found:
00668 - Supply Voltage Terminal 30 
009 - Open or Short to Ground - Intermittent
00087 - Terminal 30 for Starting Relevant Consumers 
009 - Open or Short to Ground - Intermittent
01316 - ABS Control Module 
004 - No Signal/Communication - Intermittent
00230 - Transmission Park Selector Switch (F305) 
007 - Short to Ground - Intermittent
00576 - Terminal 15 
009 - Open or Short to Ground - Intermittent
01176 - Key 
008 - Implausible Signal - Intermittent
-------------------------------------------------------------------------------
Address 06: Seat Mem. Pass Labels: 3D0-959-759.lbl
Part No: 3D0 959 759 C
Component: Sitzmemory D1 BF 1722 
Coding: 0000003
Shop #: WSC 01065 000 00000
VCID: 366722EB38D7
1 Fault Found:
00668 - Supply Voltage Terminal 30 
002 - Lower Limit Exceeded - Intermittent
-------------------------------------------------------------------------------
Address 07: Control Head Labels: 3D0-035-00x-07.lbl
Part No: 3D0 035 007 P
Component: ZAB COCKPIT 0223 
Coding: 0500535
Shop #: WSC 01065 000 00000
VCID: 2647F2ABE877
1 Fault Found:
00668 - Supply Voltage Terminal 30 
002 - Lower Limit Exceeded - Intermittent
-------------------------------------------------------------------------------
Address 08: Auto HVAC Labels: 3D0-907-040.lbl
Part No: 3D0 907 040 H
Component: Climatronic D1 2021 
Coding: 0000001
Shop #: WSC 01065 000 00000
VCID: 2341EBBF9B45
3 Faults Found:
01592 - Air Quality Sensor (G238) 
010 - Open or Short to Plus - Intermittent
01341 - Control Module in Instrument Panel On Comfort CAN (J285) 
004 - No Signal/Communication - Intermittent
00445 - Loss of Refrigerant 
000 - - - Intermittent
-------------------------------------------------------------------------------
Address 09: Cent. Elect. Labels: 3D0-937-049.lbl
Part No: 3D0 937 049 H
Component: STG.Bordnetz 5101  
Coding: 0000003
Shop #: WSC 00352 210 82926
VCID: 2F69178FC78D
2 Faults Found:
00907 - Intervention load Management 
000 - - 
00884 - Ignition Switch (D) Terminal X 
008 - Implausible Signal - Intermittent
-------------------------------------------------------------------------------
Address 11: Engine II Labels: None
Part No SW: 070 906 016 CM HW: 028 101 073 7
Component: V10 5,0L EDCG000AGSª7001 
Coding: 0000175
Shop #: WSC 00200 210 90001
VCID: 5DB59D47FDA1
5 Faults Found:
18005 - Powertrain Databus: Missing Message from Level Control System (J197) 
P1597 - 000 - - - Intermittent
Freeze Frame:
RPM: 714 /min
Torque: 110.6 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 11.17 V
Bin. Bits: 00001111
Torque: 355.5 Nm
Torque: 0.0 Nm
18036 - Powertrain Data Bus: Missing Message from Steering Angle Sensor 
P1628 - 001 - Upper Limit Exceeded - Intermittent
Freeze Frame:
RPM: 714 /min
Torque: 110.6 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 11.25 V
Bin. Bits: 00001111
Bin. Bits: 00000000
(no units): 1.0
18057 - Powertrain Data Bus: Missing Message from ABS Controller 
P1649 - 000 - - - Intermittent
Freeze Frame:
RPM: 714 /min
Torque: 110.6 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 11.25 V
Bin. Bits: 00001111
Torque: 355.5 Nm
Bin. Bits: 00000000
16625 - Manifold Pressure / Boost Sensor 2 (G447): Signal too Low 
P0241 - 000 - - - Intermittent
Freeze Frame:
RPM: 1764 /min
Torque: 173.8 Nm
Speed: 28.6 km/h
Load: 0.0 %
Voltage: 10.87 V
Bin. Bits: 00001100
Absolute Pres.: 1020.0 mbar
Absolute Pres.: 367.2 mbar
16887 - Vehicle Speed Sensor: Signal too High 
P0503 - 000 - - 
Freeze Frame:
RPM: 0 /min
Torque: 292.3 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 7.45 V
Bin. Bits: 00001100
Torque: 292.3 Nm
Torque: 0.0 Nm


----------



## feared (Aug 13, 2009)

Also

Address 17: Instruments Labels: 3D0-920-xxx-17.lbl
Part No: 3D0 920 982 
Component: KOMBIINSTRUMENT RB8 0521 
Coding: 0007411
Shop #: WSC 00225 210 91070
VCID: E5C535A755F1
5 Faults Found:
00771 - Fuel Level Sensor (G) 
010 - Open or Short to Plus - Intermittent
00439 - Fuel Supply Sensor 3 (G237) 
010 - Open or Short to Plus - Intermittent
01310 - Level Control System Control Module (J197) 
004 - No Signal/Communication - Intermittent
01316 - ABS Control Module 
004 - No Signal/Communication - Intermittent
01300 - Control Module for Navigation with CD-Rom (J401) 
004 - No Signal/Communication - Intermittent
-------------------------------------------------------------------------------
Address 18: Aux. Heat Labels: 3D0-815-005.lbl
Part No: 3D0 815 005 AA
Component: Standheizung 2426 
Shop #: WSC 01065 000 00000
VCID: 5CB39043E6BB
1 Fault Found:
02251 - Heater Unit Locked 
000 - - 
-------------------------------------------------------------------------------
Address 71: Battery Charger Labels: 3D0-915-181.lbl
Part No: 3D0 915 181 C
Component: Batteriemanagement 2700 
Shop #: WSC 00000 000 00000
VCID: 2341EBBF9B45
1 Fault Found:
00089 - Wire Monitoring for Terminal 30 Starter Battery 
007 - Short to Ground


----------



## invisiblewave (Sep 22, 2008)

Looks as if it's the ABS controller. If there's no signal, the accelerator is disabled. If you search for the thread, there's a detailed description somewhere of how they can be fixed (very difficult), or removed and sent somewhere to be fixed. I think from memory that the part is about $2000, plus a couple of hours of labour. You can't have searched that hard for the accelerator problem because there's plenty posted on it! You might find that the car will sometimes work ok for a while, until the ABS controller gets hot. I had about 10 mins from cold, then it would fail.

18057 - Powertrain Data Bus: Missing Message from ABS Controller 
P1649 - 000 - - - Intermittent
Freeze Frame:
RPM: 0 /min
Torque: 292.3 Nm
Speed: 3.6 km/h
Load: 0.0 %
Voltage: 9.27 V
Bin. Bits: 00001100
Torque: 292.3 Nm
Bin. Bits: 00000000


----------



## jyoung8607 (Feb 14, 2006)

invisiblewave said:


> Looks as if it's the ABS controller. If there's no signal, the accelerator is disabled. If you search for the thread, there's a detailed description somewhere of how they can be fixed (very difficult), or removed and sent somewhere to be fixed. I think from memory that the part is about $2000, plus a couple of hours of labour. You can't have searched that hard for the accelerator problem because there's plenty posted on it! You might find that the car will sometimes work ok for a while, until the ABS controller gets hot. I had about 10 mins from cold, then it would fail.


It could be, but many of the faults with freeze-frame data show a very deep voltage sag, well under 10V and enough to probably knock most of those modules offline briefly and interfere with lots of sensor operation. He also shows communication issues between the instrument cluster/CAN gateway and things on the infotainment and convenience CAN busses, which can't be explained solely by a failed ABS controller spamming the powertrain CAN bus as sometimes happens.

We sometimes worry too much about the batteries in these cars, like replacing them will cure any and all ills. However, there's more than enough here to justify a hard look.

To the original poster: Let's talk batteries. How old are yours? Are they factory original, or newer? If they are factory original, it's high time to replace both. If newer, are they VW/dealer spec? Check and record your voltage levels on both with the car shut down. Let us know your results.

Jason


----------



## jyoung8607 (Feb 14, 2006)

feared said:


> I've tried finding the measuring blocks for the accelerator pedal postion in VCDS but can't find them.
> 
> Any clues? I've tried Engine I and Engine II.


It should be there in multiple places, but at a minimum MVB 063 in Engine I.

You'll see two potentiometer readings going in opposite directions as you press the pedal, one going low-to-high and one going high-to-low. This is normal and expected. The pedal is designed with redundant sensors so the ECU can cross-check their results. They go in opposite directions so there's no way a wiring fault/short between the two could go un-noticed.

Jason


----------



## Tiger0002 (Apr 23, 2013)

Agreed... Check your charging/battery system to make sure the voltage is normal... normal voltage while the car is running is 14.4V.

Check batteries first with engine off for at least 30 minutes to see what the initial voltage is. If you have a battery tester, use it.

All the communication failure is meaningless if the voltage is not normal. Nothing works right at 7 to 11 volt.


----------



## invisiblewave (Sep 22, 2008)

Seems unlikely to me that a battery problem wouldn't cause any other visible symptoms than the accelerator not working, especially once the car is running. Worth checking though, prior to changing the ABS controller which ain't cheap.


----------



## Tiger0002 (Apr 23, 2013)

Everyone should always start with the basic diagnostic... and that is checking your battery voltage and charging system voltage. It is a simple 5 minutes job.

Computers and OBD are awesome diagnostic tool but is not foolproof. They are voltage sensitive and if they don't get their nominal voltage, they will report trouble codes and failures. How else can the computer run properly on low voltage? If the system is designed to run on 12V to 15V with some extra room for electrical protection from burning out (probably 16V but there is also an overvoltage protection relay/mechanism that will cut off power systemwide before it reaches there)... but it cannot compensate for low voltage.


----------



## invisiblewave (Sep 22, 2008)

Yes, I know all that, but out of all the battery problems that have been reported, I don't recall any that caused the accelerator to be disabled, and the two instances I know of that happening have both been caused by failing ABS controllers. I'm a programmer, I don't believe in coincidences, although they do sometimes happen, hence it's worth checking.


----------



## n968412L (Apr 23, 2009)

I'm sure Feared will reply in due course, but my memory of his (her??) postings over the months is that he is technically astute - so I would have thought batteries etc already considered. But as we all know, so many spurious things caused by lack of oomph in the convenience battery... I'd certainly make sure it was in tip top nick....

M


----------



## invisiblewave (Sep 22, 2008)

I seem to recall from the ABS failure discussion that it can be tested by removing the fuse. I think this was Willem's suggestion, and I think the dealer (eventually) got round to trying that but by physically disconnecting the controller, at which point the accelerator started working again.


----------



## jyoung8607 (Feb 14, 2006)

invisiblewave said:


> I seem to recall from the ABS failure discussion that it can be tested by removing the fuse. I think this was Willem's suggestion, and I think the dealer (eventually) got round to trying that but by physically disconnecting the controller, at which point the accelerator started working again.


Anything is possible, and it doesn't hurt to troubleshoot from both angles. However, the owner has posted the most impressive stack of low-voltage faults I've ever seen in this forum, with several freeze-frames around 9.3 volts and a couple in the 7 volt range. There's a battery or charging system problem with his/her car. Even if it's not THE problem, it's certainly A problem worthy of investigation.

The unresponsive accelerator pedal can be wholly explained just by the low-voltage faults the owner shared above. The code "17026 - Sensor Reference Voltage A: Circuit: Low" is a voltage sag in one of the ECU's +5V reference outputs. It's a pretty safe assumption that's due to low voltage supply to the ECU itself. The accelerator pedal potentiometers use one of those ECU +5V references. You've also got the code "18269 - Throttle Position Sensor (G79): Error Message from ECU" which indicates a problem reading the pedal potentiometers, very likely due to the ECU +5V reference circuit failing at its job of being a +5V reference. Once that check fails even once, the ECU goes into a safe operating mode ignoring the pedal until the next startup.

Jason


----------



## invisiblewave (Sep 22, 2008)

Interestingly, in addition to a new ABS controller, I also have a new ECU because the dealer suspected a failing ECU was causing the accelerator problem. They replaced the ECU first which didn't solve the problem, fortunately the warranty paid for both items.


----------



## Paximus (Aug 26, 2011)

> fortunately the warranty paid for both items


Almost goes without saying, in your case! Do they pay for your fuel too? 

CB


----------



## feared (Aug 13, 2009)

Thanks for the responses everyone.

The batteries and alternator were all replaced within the past year due to electrical power issues. The car was left standing for long periods of time so it was necessary. The car has died once since, due to a lack of use. However I have confidence in the batteries and alternator. I believe they are VW spec but again will check.

I will check MVB 063 this morning. I actually took the accelerator pedal out and checked it's got variable resistances, and checked the wiring upto the firewall. I thought it might be the kickdown switch getting stuck on, which I think causes issues with cruise control? Then again, cruise isn't on when the car is first started so this doesn't seem to be the issue.



Plan of action:
Check battery voltages
Resetting the fault codes which relate to the battery having died
Try accessing ABS controller via VCDS
MVB 063 readings

Finally to check the ABS controller I'll try pulling fuse 8 (under the instrument panel):
SB 8 - Fuse 8 (in fuse holder) 25 A -
J104 - ABS Control Module (w/EDL)
J106 - ABS Solenoid Valve Relay

Does that sound reasonable? 

I'll report back but it does sound like an ABS controller issue.


----------



## feared (Aug 13, 2009)

jyoung8607 said:


> Anything is possible, and it doesn't hurt to troubleshoot from both angles. However, the owner has posted the most impressive stack of low-voltage faults I've ever seen in this forum, with several freeze-frames around 9.3 volts and a couple in the 7 volt range. There's a battery or charging system problem with his/her car. Even if it's not THE problem, it's certainly A problem worthy of investigation.
> 
> The unresponsive accelerator pedal can be wholly explained just by the low-voltage faults the owner shared above. The code "17026 - Sensor Reference Voltage A: Circuit: Low" is a voltage sag in one of the ECU's +5V reference outputs. It's a pretty safe assumption that's due to low voltage supply to the ECU itself. The accelerator pedal potentiometers use one of those ECU +5V references. You've also got the code "18269 - Throttle Position Sensor (G79): Error Message from ECU" which indicates a problem reading the pedal potentiometers, very likely due to the ECU +5V reference circuit failing at its job of being a +5V reference. Once that check fails even once, the ECU goes into a safe operating mode ignoring the pedal until the next startup.
> 
> Jason



I'm guessing these issues are still logged from when the alternator had to be changed.

I will try resetting the codes and checking voltages (the dash meter is reading 13V).


----------



## feared (Aug 13, 2009)

invisiblewave said:


> I seem to recall from the ABS failure discussion that it can be tested by removing the fuse. I think this was Willem's suggestion, and I think the dealer (eventually) got round to trying that but by physically disconnecting the controller, at which point the accelerator started working again.


Do you know which fuse(s)? I can find 4 ABS fuses - one in the plenum chamber and 3 under the intrument panel. I can try removing fuses 8 and 61 as these are only for the ABS controller - the theory is that the accelerator should start working?


----------



## feared (Aug 13, 2009)

I've checked voltages and cleared codes. 

Tried looking in group 63 under Engine for the measuring blocks, but can't find anything to do with the accelerator. Is this the right place to be looking?


----------



## invisiblewave (Sep 22, 2008)

*Mi*

This is the thread I posted on when mine failed: http://forums.vwvortex.com/showthre...-have-it-towed&highlight=accelerator+disabled

There's another thread somewhere too, someone else had the same problem at the same time as me but his looked initially like a transmission problem.


----------



## Tiger0002 (Apr 23, 2013)

That is a critical information left out about the car had the alternator and battery replaced but the batteries has drained during lack of use.

Why was the alternator changed?

I would check ALL the fuses to see if anything is blown. Low battery voltage causes components to use more amperage than designed so there is a good chances some of the fuses will be blown.

While the car is running, if you manually accelerated the engine from the engine compartment... does the engine work normally?

When you got the car back from the mechanic, was the car able to move on its own... meaning you didn't have accelerator issue?

Did you check everything in engine compartment to make sure nothing is left disconnected?


----------



## invisiblewave (Sep 22, 2008)

feared said:


> Do you know which fuse(s)? I can find 4 ABS fuses - one in the plenum chamber and 3 under the intrument panel. I can try removing fuses 8 and 61 as these are only for the ABS controller - the theory is that the accelerator should start working?


Yes, that's the theory. It was Willem's suggestion to isolate the failing controller. As I said, once the dealer physically disconnected the ABS controller, the accelerator worked again, I assume that pulling the fuse/s will have the same effect. I don't know which fuses you'll need to pull, but I don't think you'll do any harm by pulling them.


----------



## Paximus (Aug 26, 2011)

> (the dash meter is reading 13V).


99.9% of Phaetons reportedly read 14V on the in-dash voltmeter in normal running. This is achieved as soon as the engine starts and the alternator is put on-line.

I seem to remember that Willem's was the only exception - unless my memory is playing tricks. There was one case of a corroded power cable having to be replaced.

Chris


----------



## feared (Aug 13, 2009)

The alternator was changed about 6-7 months ago as it wasn't maintaining the correct voltage. That fixed the gremlins at the time. The car had stalled at a roundabout and didn't start there so was taken to a garage.

The car reads 13V when ignition is on but engine is off, and 14V when the engine is on.

I will be back with the car tonight and will report back again.


----------



## Paximus (Aug 26, 2011)

Hi,

Thanks, that 14V reading rules out fundamental power supply issues unless your clean scan still shows a low battery.

As far as I know, the accelerator position on a V10 is only reported as a driver demand value, not as the voltages present on each of the potentiometers at the pedal. I don't know what it would say if one pot was open and the other worked. I would expect a specific fault report.

The pedal value seems to be in ECU1 MVB 8 position 2, labelled by VCDS (wrongly perhaps) as a value of 0 to 979.6 Nm. The value changes with pedal press regardless whether the engine is running or not (as long as the ECU is powered, of course).

Chris


----------



## feared (Aug 13, 2009)

Thanks Chris - I will check this tonight.


----------



## n968412L (Apr 23, 2009)

Paximus said:


> Thanks, that 14V reading rules out fundamental power supply issues unless your clean scan still shows a low battery.Chris


13V with engine not running sounds very healthy... as far as you can tell from these things.



Paximus said:


> The pedal value seems to be in ECU1 MVB 8 position 2, labelled by VCDS (wrongly perhaps) as a value of 0 to 979.6 Nm. The value changes with pedal press regardless whether the engine is running or not (as long as the ECU is powered, of course).
> 
> Chris


I was about to say"and do you know whether this is true for the V6 ECU too" when I realised that that Feared is one of the other 106 V10 owners in UK (assuming Stu (English Phaeton still has two... or did he swap one for a Bently? And where is he anyway these days...). But for completeness do you know if this is the same for the V6 TDI?

Regards

Mike


----------



## feared (Aug 13, 2009)

n968412L said:


> ...one of the other 106 V10 owners in UK


I used to have two of them


----------



## feared (Aug 13, 2009)

OK so a quick update:

I tried MVB 8 position 2, as circled in the picture. It doesn't change when the accelerator is pressed. 










This therefore seems to be an accelerator pedal or wiring issue. I've taken the accelerator pedal out and checked that its resistance changes as the pedal is pressed, so I don't think it's the pedal itself. The next stage would be to check which way the wiring goes and to check it's all intact?

Deeper down the rabbit hole...


----------



## invisiblewave (Sep 22, 2008)

Did you manage to rule out the ABS controller?


----------



## feared (Aug 13, 2009)

invisiblewave said:


> Did you manage to rule out the ABS controller?


Taking out the three fuses didn't work so I don't think it's the ABS controller


----------



## Paximus (Aug 26, 2011)

Has your scan changed from the one in posts nos 6 & 7 above?

It may be useful to make sure the accelerator pedal is reconnected, save a scan (engine running), clear all DTCs, stop and restart the engine, exercise the accelerator pedal for a short while, and scan again.

This could clear out some dross and see if the ECUs are now reporting something different.

It is possible that the Torque Demand value in MVB 08 is reported after some other software process has intervened, if not the ABS controller then some other show-stopper (there are many possibilities in the previous scan). That situation would be worthy of a DTC being flagged.

Chris


----------



## invisiblewave (Sep 22, 2008)

The other thing they looked at on mine was a faulty ECU (in fact they changed it).


----------



## Paximus (Aug 26, 2011)

> The next stage would be to check which way the wiring goes and to check it's all intact?
> feared


The accelerator pedal wiring is quite simple, the wires go from the accelerator to the ECU plug direct, no joints.



> The other thing they looked at on mine was a faulty ECU (in fact they changed it).
> invisiblewave


Did your faulty ECU flag a DTC on its self test?


Chris



*Accelerator pedal wiring*

The top unit shown is the engine ECU, the two potentiometers G185 and G79 are the pedal.
One increases the voltage while the other simultaneously decreases it.


----------



## invisiblewave (Sep 22, 2008)

I don't know for sure, but I doubt it did. They were clutching at straws. They replaced it but it didn't fix the problem, so I assume it wasn't faulty.


----------



## feared (Aug 13, 2009)

Paximus said:


> Has your scan changed from the one in posts nos 6 & 7 above?
> 
> It may be useful to make sure the accelerator pedal is reconnected, save a scan (engine running), clear all DTCs, stop and restart the engine, exercise the accelerator pedal for a short while, and scan again.
> 
> ...


I will try this when I'm next back with the car.


----------



## feared (Aug 13, 2009)

As an update, I ordered a used ABS controller from a scrapyard.

Having installed it, I'm now trying to put the correct coding in. However I keep getting one of two errors:

Coding rejected
Error 22: Conditions not correct or request sequence error

or Error 13










I believe the correct coding is 0008646 but it's currently showing 0000000


----------



## Gabs08PHTN (Jan 6, 2011)

Hi Feared,
According to VCDS coding information, you have to perform an update on both "CODING" and "CODING II".
AFAIK your coding sequence 08646 is right, but prior to that you have to enter the right code in "CODING II" which I believe is 05146. It is also mentioned that you have to perform steering angle adaptation.
For further info have a look at 3D0 614 517.LBL file on your VCDS labels directory.
I hope it helps.

Gabriel


----------



## feared (Aug 13, 2009)

Thanks! I've tried those and they work but only for a very short period of time. If I leave the control module page and go back to it, the coding resets to zeros.

I noticed a strange thing - when turning the steering wheel the steering angle sensor doesn't register any changes! The rotation rate does change a little though. 

Could that be related?


----------



## Gabs08PHTN (Jan 6, 2011)

Hi,
Together with updating the codes, did you perform a steering angle adaptation? If not, that might be the reason. 
As I mentioned on my previous post, have a look at the 3D0 614 517.LBL file within the VCDS/labels folder.

Gabriel

P.S. Read throught the following Jouko's post. At the end of #1 there is a quite clear explanation on how to adapt the steering angle sensor.


----------



## feared (Aug 13, 2009)

Thanks for that - I have now successfully coded and adapted the new ABS unit.

The problem persists (accelerator pedal dead). I've also checked the pedal itself, and am running out of ideas.

On a side note, I've searched but can't find any details of the brake bleeding procedure. Based on what I've found, there is a specific order to bleed them and there may also be some kind of VAGcom procedure to bleed the ABS pump. Has anyone done this before?


----------



## Gabs08PHTN (Jan 6, 2011)

Hi,
With regards to the accelerator issue, check engine measuring block 2.2. It is the one above the one that you circled out. And perhaps 30.1 and 30.2, these are the accelerator position senders of my engine MVB, not sure if the are the same in yours though.
In order to activate the ABS pump when bleeding the system, I seem to recall that you have to run output tests on the ABS controller. Otherwise follow the common bleeding procedure.
I hope it helps.

Gabriel


----------



## feared (Aug 13, 2009)

*Updates*

Some updates for anyone else coming across this problem. It'll be a bit of a long post 

VW kept the car for a couple of weeks, they couldn't figure out what was going on and their conclusion was basically "Let's spend about £3000 and see where that gets us".

The car still had all the lights on in the dashboard, dead accelerator pedal, 

I brought the car back, bought a second reconditioned ABS pump and fitted it. After coding and calibrating, the ABS, traction control and other warning lights are gone.

There's still no response to the accelerator pedal but I feel like I'm getting closer to the underlying problem now.


The key problem here seems to be in the Auto trans control unit, relating to the G79 sensor. Once this is fixed, it seems like the accelerator pedal should work again.

There are also faults in the Kessy and level control modules which relate to the ABS. I don't know if these will have an impact as ABS issues seem to have been fixed.

Finally, there's the G40 cam sensor error in the ECU I. 


Any ideas / comments?





Lates VCDS scan:

Chassis Type: 3D - VW Phaeton D1
Scan: 01 02 03 05 06 07 08 09 11 13 15 16 17 18 19 23 27 28 29 2E
34 36 37 38 39 46 47 55 56 57 65 66 68 69 71 75 76 77

VIN: WVWZZZ3DZ58004804 Mileage: 164050km/101935miles
-------------------------------------------------------------------------------
Address 01: Engine Labels: None
Part No SW: 070 906 016 CM HW: 028 101 073 7
Component: V10 5,0L EDCG000AGMª7001 
Coding: 0000175
Shop #: WSC 00200 210 90001
VCID: 5DB59D47FDA1

2 Faults Found:
19463 - Camshaft Position Sensor (G40): No Signal
P3007 - 000 - -
Freeze Frame:
RPM: 924 /min
Torque: 79.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 13.38 V
Bin. Bits: 00001100
Idle Stabilization: 0.0°KW
(no units): 48.0

17026 - Sensor Reference Voltage A: Circuit: Low
P0642 - 000 - -
Freeze Frame:
RPM: 924 /min
Torque: 86.9 Nm
Speed: 0.0 km/h
Bin. Bits: 00100000
Bin. Bits: 00000000
Bin. Bits: 00100000
Bin. Bits: 00100000
Bin. Bits: 00000000

Readiness: 0 0 X X X

-------------------------------------------------------------------------------
Address 02: Auto Trans Labels: None
Part No SW: 09F 927 760 C HW: GS1 9.0 4.1
Component: AG6 09F 5,0L V10TDI 1901 
Coding: 0000101
Shop #: WSC 00200 210 90001
VCID: 316D11F7D1B9

1 Fault Found:
18269 - Throttle Position Sensor (G79): Error Message from ECU
P1861 - 000 - -
Freeze Frame:
Fault Status: 01110000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 40
Mileage: 164052 km
Time Indication: 0

Freeze Frame:
RPM: 928 /min
RPM: 928 /min
RPM: 0 /min
(no units): 31.0
(no units): 32.0
Temperature: 66.0°C
T.B. Angle: 60.0°


-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 3D0-614-517.lbl
Part No: 3D0 614 517 AK
Component: ESP 5.7 allrad H33 0047 
Coding: 0008646
Shop #: WSC 01065 000 00000
VCID: 6BD1C39F3315

1 Fault Found:
01314 - Engine Control Module
013 - Check DTC Memory

-------------------------------------------------------------------------------
Address 05: Acc/Start Auth. Labels: 3D0-909-13x-05.lbl
Part No SW: 3D0 909 137 D HW: 5WK 485 08
Component: G1 Kessy 6840 
Revision: 68406418 Serial number: VWZ3Z0E1318800
Coding: 0004328
Shop #: WSC 00200 210 90001
VCID: 285BFC93E263

Part No: XXXXXXXXXXX
Component: ELV XXXX

6 Faults Found:
00668 - Supply Voltage Terminal 30 
009 - Open or Short to Ground - Intermittent
01316 - ABS Control Module
004 - No Signal/Communication - Intermittent
00576 - Terminal 15
009 - Open or Short to Ground - Intermittent
00230 - Transmission Park Selector Switch (F305)
007 - Short to Ground - Intermittent
00087 - Terminal 30 for Starting Relevant Consumers
009 - Open or Short to Ground - Intermittent
01341 - Control Module in Instrument Panel On Comfort CAN (J285)
004 - No Signal/Communication - Intermittent

-------------------------------------------------------------------------------
Address 06: Seat Mem. Pass Labels: 3D0-959-759.lbl
Part No: 3D0 959 759 C
Component: Sitzmemory D1 BF 1722 
Coding: 0000003
Shop #: WSC 01065 000 00000
VCID: 366722EB38D7

1 Fault Found:
00668 - Supply Voltage Terminal 30 
002 - Lower Limit Exceeded - Intermittent

-------------------------------------------------------------------------------
Address 07: Control Head Labels: 3D0-035-00x-07.lbl
Part No: 3D0 035 007 P
Component: ZAB COCKPIT 0223 
Coding: 0500535
Shop #: WSC 01065 000 00000
VCID: 2647F2ABE877

1 Fault Found:
00668 - Supply Voltage Terminal 30 
002 - Lower Limit Exceeded - Intermittent

-------------------------------------------------------------------------------
Address 08: Auto HVAC Labels: 3D0-907-040.lbl
Part No: 3D0 907 040 H
Component: Climatronic D1 2021 
Coding: 0000001
Shop #: WSC 01065 000 00000
VCID: 2341EBBF9B45

1 Fault Found:
01592 - Air Quality Sensor (G238)
010 - Open or Short to Plus - Intermittent

-------------------------------------------------------------------------------
Address 09: Cent. Elect. Labels: 3D0-937-049.lbl
Part No: 3D0 937 049 H
Component: STG.Bordnetz 5101 
Coding: 0000003
Shop #: WSC 00352 210 82926
VCID: 2F69178FC78D

No fault code found.

-------------------------------------------------------------------------------
Address 11: Engine II Labels: None
Part No SW: 070 906 016 CM HW: 028 101 073 7
Component: V10 5,0L EDCG000AGSª7001 
Coding: 0000175
Shop #: WSC 00200 210 90001
VCID: 5DB59D47FDA1

1 Fault Found:
17481 - Mass Air Flow Sensor 2 (G246): Signal too Low
P1073 - 000 - -
Freeze Frame:
RPM: 924 /min
Torque: 86.9 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 13.22 V
Bin. Bits: 00001100
Mass Air / Rev.: 490.0 mg/str
Mass Air / Rev.: 0.0 mg/str


-------------------------------------------------------------------------------
Address 15: Airbags Labels: 3D0-909-601.lbl
Part No: 3D0 909 601 E
Component: 0J Airbag 8.4E+ H10 0935 
Coding: 0012362
Shop #: WSC 01065 000 00000
VCID: 2545F5A79571

4 Faults Found:
01740 - Igniter for Belt-Tensioner 2; Drivers Side (N297)
001 - Upper Limit Exceeded - MIL ON
00654 - Seat Belt Tensioner Igniter; Driver Side (N153)
001 - Upper Limit Exceeded - MIL ON
01212 - Belt Tensioner Igniter; Rear Passenger Side (N197)
011 - Open Circuit - MIL ON
01211 - Belt Tensioner Igniter; Rear Driver Side (N196)
011 - Open Circuit - MIL ON

-------------------------------------------------------------------------------
Address 16: Steering wheel Labels: 3D0-953-549.lbl
Part No: 3D0 953 549 D
Component: Lenksäulenmodul 3401 
 Coding: 0000032
Shop #: WSC 01065 000 00000
VCID: 2E570A8BC087

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments Labels: 3D0-920-xxx-17.lbl
Part No: 3D0 920 982
Component: KOMBIINSTRUMENT RB8 0521 
Coding: 0007411
Shop #: WSC 00225 210 91070
VCID: E5C535A755F1

No fault code found.

-------------------------------------------------------------------------------
Address 18: Aux. Heat Labels: 3D0-815-005.lbl
Part No: 3D0 815 005 AA
Component: Standheizung 2426 
Shop #: WSC 01065 000 00000
VCID: 5CB39043E6BB

2 Faults Found:
02251 - Heater Unit Locked
000 - -
01299 - Diagnostic Interface for Data Bus (J533)
013 - Check DTC Memory - Intermittent

-------------------------------------------------------------------------------
Address 19: CAN Gateway Labels: 6N0-909-901-19.lbl
Part No: 6N0 909 901
Component: Gateway K<>CAN 0101 
Coding: 0000006
Shop #: WSC 01065 000 00000
VCID: F0EB54F39A33

1 Fault Found:
01327 - Control Module for Parking Aid (J446)
004 - No Signal/Communication

-------------------------------------------------------------------------------
Address 28: HVAC, Rear Labels: 3D0-919-158.lbl
Part No: 3D0 919 158 G
Component: Klima-Bedienteil D1 0117 
Shop #: WSC 00000 000 00000
VCID: 2F69178FC78D

No fault code found.

-------------------------------------------------------------------------------
Address 29: Left Light Labels: 3D0-909-157.lbl
Part No: 3D0 909 157
Component: EVG GDL+AutoLWR(l) 0001 
Coding: 0000001
Shop #: WSC 01065 000 00000
VCID: E6C732ABA8F7

No fault code found.

-------------------------------------------------------------------------------
Address 34: Level Control Labels: 3D0-907-553.lbl
Part No: 3D0 907 553 C
Component: LUFTFDR.-CDC- 3C3V0 1122 
Coding: 0005531
Shop #: WSC 01065 000 00000
VCID: 2759FFAFEF7D

3 Faults Found:
01316 - ABS Control Module
004 - No Signal/Communication - Intermittent
00477 - Control Module; Display & Input; Comfort CAN; Front (J523)
004 - No Signal/Communication - Intermittent
00062 - Suspension Function Request
004 - No Signal/Communication - Intermittent

-------------------------------------------------------------------------------
Address 36: Seat Mem. Drvr Labels: 3D0-959-760.lbl
Part No: 3D0 959 760 B
Component: Sitzmemory D1 F 1522 
Coding: 0000004
Shop #: WSC 01065 000 00000
VCID: 2D550D87CD81

2 Faults Found:
00668 - Supply Voltage Terminal 30 
002 - Lower Limit Exceeded - Intermittent
00466 - Control Module for Steering Column Electronics (J527)
004 - No Signal/Communication - Intermittent

-------------------------------------------------------------------------------
Address 37: Navigation Labels: 3D0-919-887.lbl
Part No: 3D0 919 887 E
Component: NAVIGATION 0168 
Coding: 0400000
Shop #: WSC 01065 000 00000
VCID: 366722EB38D7

No fault code found.

-------------------------------------------------------------------------------
Address 38: Roof Electronics Labels: 3D0-907-135.lbl
Part No: 3D0 907 135 B
Component: Dachmodul 0605 
Coding: 0000015
Shop #: WSC 01065 000 00000
VCID: 224FEEBB845F

1 Fault Found:
00926 - Terminal 30
002 - Lower Limit Exceeded - Intermittent

-------------------------------------------------------------------------------
Address 39: Right Light Labels: 3D0-909-158.lbl
Part No: 3D0 909 158
Component: EVG GDL+AutoLWR(r) 0001 
Coding: 0000001
Shop #: WSC 01065 000 00000
VCID: E7D93FAFAFFD

No fault code found.

-------------------------------------------------------------------------------
Address 46: Central Conv. Labels: 3D0-959-933.lbl
Part No: 3D0 959 933 F
Component: 29 HSG 0101 
Coding: 0000040
Shop #: WSC 01065 000 00000
VCID: 33611BFF2BA5

Part No: 3D2 959 701 D
Component: Tuersteuergeraet FS 0201

Part No: 3D2 959 702 D
Component: Tuersteuergeraet BF 0201

Part No: 3D0 959 703 D
Component: Tuersteuergeraet HL 0201

Part No: 3D0 959 704 D
Component: Tuersteuergeraet HR 0201

Part No: 3D0 909 610 C
Component: 3L HDSG 2330

Part No: 7L0 907 719
Component: Neigungssensor 0020

14 Faults Found:
01516 - Terminal 30; Left
011 - Open Circuit - Intermittent
00926 - Terminal 30
011 - Open Circuit - Intermittent
00668 - Supply Voltage Terminal 30 
002 - Lower Limit Exceeded - Intermittent
00576 - Terminal 15
008 - Implausible Signal - Intermittent
01141 - Luggage Compartment Unlocking Switch (E165)
007 - Short to Ground - Intermittent
00325 - Rear Window Opening Button (E361)
007 - Short to Ground - Intermittent
01134 - Alarm Horn (H12)
004 - No Signal/Communication - Intermittent
00987 - Lamp for Brake Light; Left (M9)
009 - Open or Short to Ground - Intermittent
01331 - Door Control Module; Driver Side (J386)
002 - Lower Limit Exceeded - Intermittent
01332 - Door Control Module; Passenger Side (J387)
002 - Lower Limit Exceeded - Intermittent
01333 - Door Control Module; Rear Left (J388)
002 - Lower Limit Exceeded - Intermittent
01334 - Door Control Module; Rear Right (J389)
002 - Lower Limit Exceeded - Intermittent
00318 - Supply Voltage for Rear Lid Control Module
002 - Lower Limit Exceeded - Intermittent
00896 - Trunk Lock Unit (F256)
008 - Implausible Signal - Intermittent

-------------------------------------------------------------------------------
Address 47: Sound System Labels: 7Lx-035-4xx-47.lbl
Part No: 3D0 035 466 A
Component: 12K-AUDIOVERST 0118 
Shop #: WSC 00000 000 00000
VCID: 204BE4B38A53

No Faults Found
or DTCs not supported by controller
or a communication error occurred

-------------------------------------------------------------------------------
Address 57: TV Tuner Labels: 3D0-919-146.lbl
Part No: 3D0 919 146
Component: TV Tuner H07 1205 
Coding: 0000010
Shop #: WSC 01065 000 00000
VCID: E5C535A755F1

No fault code found.

-------------------------------------------------------------------------------
Address 66: Seat, Rear Labels: 3D0-959-860.lbl
Part No: 3D0 959 860 C
Component: Sitzmemory D1 H 1722 
Coding: 0000001
Shop #: WSC 00000 000 00000
VCID: 2F69178FC78D

1 Fault Found:
00668 - Supply Voltage Terminal 30 
002 - Lower Limit Exceeded - Intermittent

-------------------------------------------------------------------------------
Address 68: Wiper Electr. Labels: Redir Fail!
Part No: 3D2 955 120
Component: Front Wiper 3000 
Shop #: WSC 00000 000 00000
VCID: DFC9274F77AD

No fault code found.

-------------------------------------------------------------------------------
Address 71: Battery Charger Labels: 3D0-915-181.lbl
Part No: 3D0 915 181 C
Component: Batteriemanagement 2700 
Shop #: WSC 00000 000 00000
VCID: 2341EBBF9B45

3 Faults Found:
00085 - Starter Battery Switch-Over Relay (J580)
012 - Electrical Fault in Circuit - Intermittent
00086 - Parallel Battery Connection Relay (J581)
012 - Electrical Fault in Circuit - Intermittent
00576 - Terminal 15
008 - Implausible Signal - Intermittent

-------------------------------------------------------------------------------
Address 77: Telephone Labels: 3D0-035-704.lbl
Part No: 3D0 035 704 D
Component: Telefon 8110 
Shop #: WSC 00000 000 00000
VCID: 1E37DA4BB027

No fault code found.

End ---------------------------------------------------------------------


----------



## PanEuropean (Nov 3, 2001)

Well.... here's my take on the diagnostic scan. I am afraid it is not good news for you.

Normally I disregard 'intermittent' faults on a scan, but in this particular case, because of the nature of the difficulties that you are having (basically, the car won't operate at even the lowest functional level - it won't respond to accelerator pedal input), I'm going to give a little more consideration than normal to the many intermittent faults you have.

*In aggregate*, looking at all of the various hard and intermittent faults, and the general nature of them (electrical), I think that your car is close to being FUBAR. In other words, it might be time to start thinking about palliative care rather than repair.

Here's my rationale: The vehicle has an enormous amount of unrelated electrical problems. You have electrical problems with the engine, transmission, access and start control system, air conditioning, park distance control, level control system, numerous cabin doors, exterior lamps, various switches, and the battery manager. On top of all this, the faults listed in the airbag controller strongly suggest that the vehicle has been in an accident and numerous airbags have deployed.

How well do you know the history of the car? Was it ever totally trouble free during your term of ownership? Do you know what the story on the accident and subsequent repair of accident damage is? If the accident was serious - and it appears to have been more than just a parking lot fender-bender - then the root cause of all of your difficulty might be electrical system damage arising from the accident, or poor quality repair of electrical wiring that was damaged in the accident.

Although I hate to say it - and I have never said this before here in the forum - I kind of think that this particular vehicle is BER (Beyond Economical Repair).

Michael


----------



## invisiblewave (Sep 22, 2008)

Another easy thing you might try, if you haven't already, is WillemBal's suggestion to pull each controller fuse one at a time to see if there's one controller causing a cascade of errors. It sounds like a long shot after reading Michael's post, but worth a try. If the dealer had done that with mine they would have diagnosed the ABS problem in an hour, rather than the 3 weeks (and new ECU) it took them.


----------



## feared (Aug 13, 2009)

PanEuropean said:


> Well.... here's my take on the diagnostic scan. I am afraid it is not good news for you.
> 
> Normally I disregard 'intermittent' faults on a scan, but in this particular case, because of the nature of the difficulties that you are having (basically, the car won't operate at even the lowest functional level - it won't respond to accelerator pedal input), I'm going to give a little more consideration than normal to the many intermittent faults you have.
> 
> ...


It's a tough pill to swallow, but you might be right.

I know the whole history of the car and we bought as accident damaged and repaired it. It was trouble free for the first few months but then the usual gremlins started appearing. We had the alternator and batteries replaced along with some of the other engine and drivetrain components.

As far as I see the errors, as long as the car becomes driveable again at least it can be used for a while. 

The errors I'd like to fix are:
1. Throttle position sensor
2. Any ABS communication issues
3. Supply Voltage Terminal 30
4. Camshaft position sensor

After the first two faults are fixed the car should become driveable again. 




invisiblewave said:


> Another easy thing you might try, if you haven't already, is WillemBal's suggestion to pull each controller fuse one at a time to see if there's one controller causing a cascade of errors. It sounds like a long shot after reading Michael's post, but worth a try. If the dealer had done that with mine they would have diagnosed the ABS problem in an hour, rather than the 3 weeks (and new ECU) it took them.



Do you know if the ABS controller will require recoding after any of these steps? I'll try that when I'm next with the car. I did previously try disconnecting the ABS controller entirely.


----------



## invisiblewave (Sep 22, 2008)

feared said:


> Do you know if the ABS controller will require recoding after any of these steps? I'll try that when I'm next with the car. I did previously try disconnecting the ABS controller entirely.


Are you talking about coding or adaptation? The coding on my ABS controller is 0008376. I don't know whether or not it requires adaptation.


----------



## PanEuropean (Nov 3, 2001)

feared said:


> Do you know if the ABS controller will require recoding after any of these steps?


No. Assuming you have not replaced the controller with a different one, the coding will remain the same. As Martin pointed out, you may need to re-adapt the controller (drive in a figure of eight), but you should not need to recode it.



feared said:


> I did previously try disconnecting the ABS controller entirely.


Not a good idea at all. The car simply will not function without that controller. You can disconnect *convenience/comfort* and *entertainment *controllers and get away with it, but you cannot and must not attempt to disconnect *drivetrain *controllers. Have a look at the system topology description at this post: Phaeton controller addresses, controller network topology

Because you have disconnected some controllers, you may need to refresh the CAN gateway in order to get the car to re-recognise them. See this post: Requirement to Refresh the CAN gateway (Controller 19) after Controller Retrofits or Controller Removal

Michael


----------



## invisiblewave (Sep 22, 2008)

The car does work with the ABS controller disconnected, surprisingly. That's how the dealer eventually diagnosed mine, they said as soon as they physically disconnected it the accelerator started working.


----------



## PanEuropean (Nov 3, 2001)

invisiblewave said:


> The car does work with the ABS controller disconnected, surprisingly.


I'm not certain about this, but I think that if the ABS controller is disconnected or fails, the car will work in a 'degraded' or 'limp' mode.

Michael


----------



## invisiblewave (Sep 22, 2008)

It goes into limp mode if it fails, the car starts but the accelerator is disabled so you can only move it at idle speed. When it's disconnected, everything apparently works again.


----------



## Paximus (Aug 26, 2011)

Hello Hira,

The car is clearly in emergency running mode, which could disable the accelerator pedal operation whether it is faulty or not. [edit - as Invisiblewave said]

At this point please can we re-cap? 

1. Is the above scan after clearing all DTCs and then running the engine and exercising the gearshift, brakes etc for a while? Or was it done after having disconnected and reconnected some controller plugs without subsequently clearing the faults using VCDS?

2. In the latest scan, some controller addresses are not included. Is that due to editing, or does the car's Gateway need resetting to restore their comms?

3. Which significant controller parts have been changed in total?

-- I see that the engine ECUs were 070 906 016 B but are now 070 906 016CM 
-- Transmission controller was 09F 927 760C but is now 09F 927 760B
-- Kessy was 3D0 909 135 N and now 3D0 909 137D 

4. Was the above scan done after changing a controller, since when the car has not run normally at all? Or was there a period of reasonably normal running after the latest controller change?

5. Are you confident that the security codes are matched on the critical drivetrain and KESSY CAN-bus comms (normally done by a dealer)? They are all supposed to match, but rumour has it that one (only) controller can be changed, ie have a non-matching security code, after which a second substitution will break the drivetrain CAN-bus comms until they are all re-set. Perhaps someone here has better information on this aspect.


I agree with Michael's gloom if the scan was a result of degredation while the car was in regular use, but if the scan issues are partly due to hands-on diagnostic actions then there is probably some hope! Electronics are not (usually) operated by magic, although some fellow software practitioners here may sometimes feel otherwise... 

Chris


----------



## jyoung8607 (Feb 14, 2006)

feared said:


> 17026 - Sensor Reference Voltage A: Circuit: Low
> P0642 - 000 - -


I think this is the root cause of your problems.

As I mentioned in an earlier post, the ECU generates two (I think) 5V reference sources for shared use with several sensors. The DTC above means that +5V reference isn't +5V, which is a problem. That means something is shorting it to ground, or the ECU is failed, or both -- a continued short to ground might have damaged your new ECU. Your accelerator pedal is measured against that reference, as are several other sensors. On gas engines I believe the throttle bodies use them, but yours is diesel. All the rest of the OMGWTFBBQ in your scan is probably low-battery fallout, diagnostic fallout or parts-being-thrown-at-it fallout.

Unfortunately VW's wiring diagrams don't make it clear which sensors use a +5V reference on your car, much less which one. I can give you some educated guesses, and we can guess for the moment the stuff that's only connected to ECU 2 (address 11) is mostly okay. I think anything that works as a potentiometer is in play. I believe if you clear the engine codes, they will return immediately or return the next time you try to start the engine. I suggest this course of action:

1) As described above, clear codes and make sure they come back. Both are showing as current - not Intermittent - so I believe they will.

2) Start disconnecting sensors, one by one. Repeat #1 and see what happens. We may expect to see a DTC for that sensor pop up, and that is fine. What we're looking for is absence of the 17026 "Sensor Reference Voltage A: Circuit: Low" DTC. We're looking for something which, when disconnected, stops the +5V reference line being pulled low.

3) If that doesn't work, there is a short hiding in the engine wiring harness somewhere, or your new ECU is damaged, or both. Good luck on that.

Here are my _complete guesses_ as to which sensors to try, roughly in order they might be involved.

Most likely, because of DTCs in your scan:
G40 Hall Sender (Cam Position Sensor), not sure whether this will use +5V but you have a consistent DTC
G31 Charge Pressure Sender 1 / G42 Intake Air Temperature Sender 1 (appears to be a single device), mentioned when others troubleshoot this
G79 Accelerator Position Sensor (your accelerator pedal)
G246 Air Mass Meter 2, Bank 2 (MAF sensor), hooked up to ECU 2 but some shared wiring with MAF 1 and has a DTC

Good possibilities, hooked up to ECU 1:
G70 Air Mass Meter, Bank 1 (MAF sensor)
G28 Engine Speed Sender / Crank Position Sensor (not sure whether this will use +5V)
G62 Coolant Temperature Sender
G83 Radiator Outlet Coolant Temperature Sender
G81 Fuel Temperature Sender
G133 Fuel Composition Sender

Less likely, hooked up to ECU 2:
G447 Charge Pressure Sender 2 / G299 Intake Air Temperature Sender 2 (appears to be a single device)
Some other stuff I haven't bothered to list

If in doubt, just clear codes and then disconnect everything you can find. Turn the car on, read the blizzard of DTCs and see if the reference voltage DTC came back. If it didn't, reconnect things one by one till you find the trigger.

Jason


----------



## jyoung8607 (Feb 14, 2006)

feared said:


> I know the whole history of the car and we bought as accident damaged and repaired it. It was trouble free for the first few months but then the usual gremlins started appearing. We had the alternator and batteries replaced along with some of the other engine and drivetrain components.


Chris already spotted a new TCM and KESSY, and you also probably have a new airbag control module. Please provide as many specific details as you can, like where it was damaged and what components have been replaced for any reason, including ones you think don't matter. You might be shocked at some of the inter-dependencies. 

Jason


----------



## feared (Aug 13, 2009)

Apologies for the long post but here goes.

I've made some progress in diagnosis. There was some damaged wiring at the front of the car, I will dig out pictures when I'm back on the VCDS laptop. 

The damaged wires may have shorted. The wires being damaged may explain the G40 cam sensor error, perhaps the sensor has been fried?

Furthermore, based on other peoples experiences with Passats and the G79 error (e.g. here), this shorting of wires may have fried an ECU.

I need to go through the SSPs and wiring diagrams to find out what this wiring connects to at both ends.



Paximus said:


> 1. Is the above scan after clearing all DTCs and then running the engine and exercising the gearshift, brakes etc for a while? Or was it done after having disconnected and reconnected some controller plugs without subsequently clearing the faults using VCDS?
> 
> 2. In the latest scan, some controller addresses are not included. Is that due to editing, or does the car's Gateway need resetting to restore their comms?
> 
> ...


1. The above scan is after some other diagnostics and with a little bit of driving but not much as the car isn't roadworthy without the accelerator. The batteries may have been disconnected in order to test and recharge and this might be the cause of the voltage errors.

2. Which controller addresses are missing? I'll check on the diagnostic laptop for the original file as it may well have been edited.

3. I'll go into this at the end of the post

4. The latest controller change was the ABS controller and the car has not been run significantly since this change

5. I haven't changed any drivetrain or KESSY codes or adjusted their functionality. The KESSY was previously replaced due to getting waterlogged.

Most of the issues are due to hands-on diagnostics  the Phaeton can be magical to drive but it often seems like the electronics are operated by the dark arts :banghead: 




jyoung8607 said:


> 1) As described above, clear codes and make sure they come back. Both are showing as current - not Intermittent - so I believe they will.
> 
> 2) Start disconnecting sensors, one by one. Repeat #1 and see what happens. We may expect to see a DTC for that sensor pop up, and that is fine. What we're looking for is absence of the 17026 "Sensor Reference Voltage A: Circuit: Low" DTC. We're looking for something which, when disconnected, stops the +5V reference line being pulled low.
> 
> ...


I've added numbers to the groups of problems. Parts 2. and 3. can be ignored as those parts were undone for various reasons such as installing the new ABS controller.

The main errors as I see it are G79 throttle and G40 cam position. I may have found part of the reason.

When you say disconnect everything you can find, what should I start with? Is this all the faulty sensors, or all the sensors I can find which are attached to a given controller?



jyoung8607 said:


> Chris already spotted a new TCM and KESSY, and you also probably have a new airbag control module. Please provide as many specific details as you can, like where it was damaged and what components have been replaced for any reason, including ones you think don't matter. You might be shocked at some of the inter-dependencies.
> 
> Jason


Some history:
When we bought the car as damaged, it wouldn't start. After about a month at VW and a large bill, they found that someone had switched the ECUs by accident and that was causing all the problems. Some of the airbags were replaced, but I'm not sure if the airbag controller was replaced. The car ran fine for a while, then the KESSY was flooded and we had it replaced by VW. More recently we had the batteries and alternator changed (just over a year ago) by an independent specialist and this is why I think those components are fine. 

Conclusions
Due to the damaged wiring, it could well be a short circuit or damaged ECU. This manifests itself in the throttle error, cam sensor error and voltage error. 

Plan of action
Clear all codes, drive the car at idle speed for a few hundred meters, and scan again
Find out what was connected to each end of the damaged wiring (I suspect this is the ECU I and Cam sensor)
Disconnect sensors until the voltage errors disappear
Inspect and test the cam sensor G40 (probably a hall effect sensor)

Does this sound reasonable?


----------



## PanEuropean (Nov 3, 2001)

feared said:


> Does this sound reasonable?


I'm not sufficiently on top of electrical diagrams to comment on your plan on a "liine by line" basis, but in broad terms, your plan sounds pretty reasonable and quite well thought out.

You might want to keep in mind the concept of "paths of influence" when you set out your troubleshooting plan. In other words, try and work out (on paper) which faults relate to each other, and then approach each group of related faults as a collective task. Doing this will likely reduce the amount of time you spend fault-finding and troubleshooting.

Also, don't forget the 'little gotcha's', such as maintaining battery voltage, clearing faults after each intervention, and if a controller is momentarily disconnected, refreshing the CAN gateway to make sure that the car is seeing that controller.

Michael


----------



## feared (Aug 13, 2009)

Does anyone know what these connectors lead to? My first guess would be cam sensors. These wires were broken and shorted. 

This seems to be the root of all of these problems.


----------



## PanEuropean (Nov 3, 2001)

feared said:


> These wires were broken and shorted... This seems to be the root of all of these problems.


Uh, yes, you could be onto something there... 

Michael


----------



## findre (Jan 15, 2008)

*g79 probs*

what eventually happened, did you find the fault? i am having the same issue, g79 and voltage problems. also cant seem to find the g40 CPS plug.....elsawin doesn't do a great job.,...at least the version I have.


----------



## Karl H (Nov 16, 2018)

Uhhh, yes. Definitely would have good to know what happened in the end. Having exactly the same issue.


----------

