# P0134 O2 Sensor Sensor Circuit No Activity



## 7rrivera7 (Jun 24, 2010)

2000 Jetta VR6:

Idled fine before replacing the pre-cat O2 sensor with a new Bosch unit since the original O2's wiring was frayed. Now the idle during a cold start is horrible and the engine misses until it warms up. The CTS is a new "green" unit so that gets eliminated from being a possible culprit.

With the new O2 plugged in, a scan gives me the following:

16518 - Oxygen (Lambda) Sensor B1 S1 
P0134 - 35-00 - No Activity

If I unplug the O2 sensor, the car idles great both cold and warm and a scan gives me the following:

16518 - Oxygen (Lambda) Sensor B1 S1 
P0134 - 35-00 - No Activity
17524 - Oxygen (Lambda) Sensor Heating; B1 S1 
P1116 - 35-00 - Open Circuit

This tells me the PCM detected that I unplugged the O2 sensor so I guess most of the wiring is good but I'm thinking one (or more?) wire(s) is open/shorted since I get "no activity" with the O2 plugged in.

I'm ready to trace the O2 wiring but I having difficulty in reading the diagram in the Bentley. The O2 sensor has 5 wires as follows:

red, white, yellow, black, grey

The O2 wiring harness has 6 wires as follows:

green, blue/yellow stripe, orange, orange(2), white, black

When connected, the color to color matching is as follows:

O2 black to connector green
O2 grey to connector blue/yellow stripe
O2 yellow to connector orange
O2 red to connector orange(2)
O2 white to connector white
O2 (open) to connector black

As shown, the O2 sensor has 5 wires and the harness connector has 6 - the black wire on the O2 connector has nothing coming from the sensor. Is it possible I bought the wrong sensor and the black wire is the signal which shows "no activity"? The original O2 sensor with frayed wiring was also a 5-wire unit.

Sorry for the lenghty post but I think more details is better than less right?

Thanks!


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## vdubtech398 (Jul 19, 2007)

Not sure about the rough idle caused by new O2 sensor, but VW issued a software update/ECM software update for the P0134 concern on VR6's like the one you have, I would call a local dealer and ask them to run your VIN and check for an N7/26E1 campaign/ reflash.

Maybe try cleaning your throttle body to clear up your cold start rough idle.


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## [email protected] Parts (Nov 27, 2006)

Respectfully you need to post an auto-scan to commence here.

We would know for sure if he needed an N7 update if there was this thing called an....


AUTO-SCAN!


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## 7rrivera7 (Jun 24, 2010)

No problem - thought the info posted was sufficient for the cause at hand. Here is an autoscan:

VCDS Version: Release 11.11.3 (x64)
Data version: 20120401

Wednesday,16,May,2012,08:30:52:26610

Chassis Type: 9M - VW Jetta IV
Scan: 01 02 03 08 09 15 16 17 19 22 29 35 36 37 39 46 47 55 56 57
75 76

Mileage: 130380km/81014miles
-------------------------------------------------------------------------------
Address 01: Engine Labels: 021-906-018-AFP.lbl
Part No: 021 906 018 K
Component: MOTRONIC ME7.1 G V06 
Coding: 00033
Shop #: WSC 00862 
VCID: 162D3A84729CBC9

2 Faults Found:
16518 - Oxygen (Lambda) Sensor B1 S1 
P0134 - 35-00 - No Activity
17524 - Oxygen (Lambda) Sensor Heating; B1 S1 
P1116 - 35-00 - Open Circuit
Readiness: 0000 1101

-------------------------------------------------------------------------------
Address 02: Auto Trans Labels: 01M-927-733.lbl
Part No: 01M 927 733 JS
Component: AG4 Getriebe 01M 4834 
Coding: 00000
Shop #: WSC 00000 
VCID: 8A15DEF4B624E89

1 Fault Found:
00777 - Accelerator Position Sensor (G79) 
27-10 - Implausible Signal - Intermittent

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 1J0-907-37x-ABS.lbl
Part No: 1J0 907 379 R
Component: ASR 20 IE CAN 0001 
Coding: 13204
Shop #: WSC 00066 
VCID: 4081BCDC4098E29

1 Fault Found:
01276 - ABS Hydraulic Pump (V64) 
16-00 - Signal Outside Specifications

-------------------------------------------------------------------------------
Address 08: Auto HVAC Labels: 3Bx-907-044.lbl
Part No: 3B1 907 044 A
Component: CLIMATRONIC S 9.0 
Coding: 01000
Shop #: WSC 00066 
VCID: 1F431FA09DA6FD1

3 Faults Found:
00792 - A/C Pressure Switch (F129) 
35-00 - - 
01206 - Signal for Duration of Ignition Off Time 
35-00 - - 
00281 - Vehicle Speed Sensor (G68) 
35-10 - - - Intermittent

-------------------------------------------------------------------------------
Address 15: Airbags Labels: 6Q0-909-605-VW5.lbl
Part No: 6Q0 909 605 A
Component: 09 AIRBAG VW5 0003 
Coding: 12345
Shop #: WSC 00066 
VCID: 356FDD080F5A571

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments Labels: 1J0-920-xx0-17.lbl
Part No: 1J0 920 920 D
Component: A4-KOMBIINSTR. VDO V54 
Coding: 07262
Shop #: WSC 08701 
VCID: 254F0D48BFFA271

Subsystem 1 - Part No: IMMO
Component: IDENTNR: VWZ7Z0X1298917 
IMMO-IDENTNR: VWZ7Z0X1298917 

No fault code found.

-------------------------------------------------------------------------------
Address 19: CAN Gateway Labels: 6N0-909-901-19.lbl
Part No: 6N0 909 901 
Component: Gateway KCAN 0001 
Coding: 00007
Shop #: WSC 00066 
VCID: F0E1AC1CB0B8B29

No fault code found.

-------------------------------------------------------------------------------
Address 36: Seat Mem. Drvr Labels: None
Part No: 3B1 9€9 760 A
Component: Sitzverstellung FS 0003 
VCID: 76ED1A0452DC1C9

4 Faults Found:
00668 - Supply Voltage Terminal 30 
06-10 - Signal too High - Intermittent
00668 - Supply Voltage Terminal 30 
07-10 - Signal too Low - Intermittent
01330 - Central Control Module for Central Convenience (J393) 
49-10 - No Communications - Intermittent
01009 - Sensor for Driver's Seat Position Fore/Aft (G218) 
36-00 - Open Circuit

-------------------------------------------------------------------------------
Address 46: Central Conv. Labels: 1J0-959-799.lbl
Part No: 1J0 959 799 AJ
Component: 61 Zentral-SG Komf. 0001 
Coding: 04098
Shop #: WSC 00066 
VCID: 860DEAC4A23C8C9

Subsystem 1 - Part No: 1J1959801C
Component: 61 Tõrsteuerger. FS0002r 

Subsystem 2 - Part No: 1J1959802D
Component: 61 Tõrsteuerger. BF0002r 

Subsystem 3 - Part No: 1J4959811C
Component: 61 Tõrsteuerger. HL0002r 

Subsystem 4 - Part No: 1J4959812C
Component: 61 Tõrsteuerger. HR0002r 

6 Faults Found:
01330 - Central Control Module for Central Convenience (J393) 
53-10 - Supply Voltage Too Low - Intermittent
01179 - Incorrect Key Programming 
35-00 - - 
01331 - Door Control Module; Driver Side (J386) 
53-10 - Supply Voltage Too Low - Intermittent
01332 - Door Control Module; Passenger Side (J387) 
53-10 - Supply Voltage Too Low - Intermittent
01333 - Door Control Module; Rear Left (J388) 
53-10 - Supply Voltage Too Low - Intermittent
01334 - Door Control Module; Rear Right (J389) 
53-10 - Supply Voltage Too Low - Intermittent

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


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## [email protected] Parts (Nov 27, 2006)

Thank you for posting the auto-scan.
THIS POST MOVED/VACATED BY JACK TO PROTECT CONTENT FALLING INTO THE GAPING HOLE OF THE VORTEX

IT SEEMS NO GOOD DEED GOES UNPUNISHED!

http://www.youtube.com/watch?v=HaoySOGlZ_U


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## 7rrivera7 (Jun 24, 2010)

Thank you Jack.

The MAF is new and so are both O2 sensors. Readiness is not complete because the car is in my garage on stands while I resolve various suspension issues. It hasn't been driven for more than 5 minutes in the last few months and the battery has been disconnected.

Can you validate that even though the primary O2 sensor has only 5 wires and the O2 harness connector has 6, this is normal? I'd like to tackle one problem at a time and since the O2 sensor has "no activity" when plugged in, I need to know if the wiring is correct since the orioginal O2 wiring was frayed.

The key message I want to present is that with the O2 plugged in, my cols start idle is horrible and when it is unplugged, the idle is smooth. This leads me to believe the "no activity" response from the PCM is causing the bad idle.


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## 7rrivera7 (Jun 24, 2010)

When you say I need the firmware update, is this at the dealer under a TSB? Do you have info on this? Thanks again!


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## Dana @ Ross-Tech (Sep 15, 2009)

7rrivera7 said:


> When you say I need the firmware update, is this at the dealer under a TSB? Do you have info on this? Thanks again!


N7 (26E1) was a recall issues in 2006 or 2007 for all AFP Vr6 vehicles in the US market and should be completed free of charge on any vehicles with a clean title providing the action is open on this VIN. That particular module (021 906 018 K) would be updated from the SWL of V06 to 6758 or higher.


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## [email protected] Parts (Nov 27, 2006)

THIS POST MOVED/VACATED BY JACK TO PROTECT CONTENT FALLING INTO THE GAPING HOLE OF THE VORTEX

IT SEEMS NO GOOD DEED GOES UNPUNISHED!

http://www.youtube.com/watch?v=HaoySOGlZ_U


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## 7rrivera7 (Jun 24, 2010)

[email protected] Parts said:


> Validated it has an extra pin for the 6th.


Thank you so much for validating this for me Jack!

...so the O2 sensor has 5 wires in a 6-pin connector and even though the 6th pin is not connected to anything, this is by design and not the cause of my "no activity" O2 code.

It's time to trace the 5 wires into the PCM. Anyone know what pins these 5 wires go to on the PCM? I have the Bentley and if someone can help me understand the wiring diagrams, I can help myself


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## [email protected] Parts (Nov 27, 2006)

THIS POST MOVED/VACATED BY JACK TO PROTECT CONTENT FALLING INTO THE GAPING HOLE OF THE VORTEX

IT SEEMS NO GOOD DEED GOES UNPUNISHED!

http://www.youtube.com/watch?v=HaoySOGlZ_U


----------



## 7rrivera7 (Jun 24, 2010)

[email protected] Parts said:


> CORRECT
> 
> You must find a different path of attack.
> 
> Use VCDS to watch OXS in 01-04-034 for B1 S1.


Will attempt this and report back...


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## [email protected] Parts (Nov 27, 2006)

THIS POST MOVED/VACATED BY JACK TO PROTECT CONTENT FALLING INTO THE GAPING HOLE OF THE VORTEX

IT SEEMS NO GOOD DEED GOES UNPUNISHED!

http://www.youtube.com/watch?v=HaoySOGlZ_U


----------



## 7rrivera7 (Jun 24, 2010)

Ok, I've got the logs requested but I'm not allowed to post attachments. How can I get the 3 .CSV files to you?


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## 7rrivera7 (Jun 24, 2010)

Jack I sent the logs to: [email protected]. Hope this is what you intended


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## [email protected] Parts (Nov 27, 2006)

Nope please post them here for everyone to see.


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## 7rrivera7 (Jun 24, 2010)

Ok, I tried formatting as best I could before copying. Saw the "TEST OFF" column but don't understand VCDS enough to turn it on...

*OXS in 01-04-034 for B1 S1*

Friday 18	May	2012	21:05:49:26610	VCDS Version: Release 11.11.3 (x64)	Data version: 20120401 
021 906 018 K MOTRONIC ME7.1 G V06 

Group A:	'034 Group B: Not Running	Group C: Not Running
Engine Speed	Catalytic Converter	Dynamic Factor	Result 
TIME	(G28)	Bank 1 Temp.	Bank 1 Sensor 1	Lambda Aging	TIME TIME	
Marker	STAMP /min	°C STAMP STAMP	
0.01	920	340	0.797	Test OFF 
0.3	880	340	0.797	Test OFF 
0.6	800	335	0.797	Test OFF 
0.9	840	335	0.797	Test OFF 
1.2	800	335	0.797	Test OFF 
1.5	840	335	0.797	Test OFF 
1.8	800	335	0.797	Test OFF 
2.1	880	330	0.797	Test OFF 
2.4	840	330	0.797	Test OFF 
2.7	720	330	0.797	Test OFF 
3	760	330	0.797	Test OFF 
3.3	760	330	0.797	Test OFF 
3.6	760	330	0.797	Test OFF 
3.9	800	330	0.797	Test OFF 
4.2	800	325	0.797	Test OFF 
4.5	800	325	0.797	Test OFF 
4.8	840	325	0.797	Test OFF 
5.1	800	325	0.797	Test OFF 
5.4	760	325	0.797	Test OFF 
5.7	760	325	0.797	Test OFF 
6	720	320	0.797	Test OFF 
6.3	760	320	0.797	Test OFF 
6.6	760	320	0.797	Test OFF 
6.9	720	320	0.797	Test OFF 
7.2	760	320	0.797	Test OFF 
7.49	760	320	0.797	Test OFF 
7.8	760	315	0.797	Test OFF 
8.1	800	315	0.797	Test OFF 
8.4	800	315	0.797	Test OFF 
8.7	720	315	0.797	Test OFF 
9	720	315	0.797	Test OFF 
9.3	720	315	0.797	Test OFF 
9.6	680	315	0.797	Test OFF 
9.9	640	315	0.797	Test OFF 
10.2	680	310	0.797	Test OFF 
10.5	760	310	0.797	Test OFF 
10.8	720	310	0.797	Test OFF 
11.1	760	310	0.797	Test OFF 

*OXS in 01-04-031 for B1 S1*

Friday	18	May	2012	21:14:59:26610	VCDS Version: Release 11.11.3 (x64)
021 906 018 K MOTRONIC ME7.1 G V06 

Group A:	'031 
Lambda Control	Lambda Control	Bin. Bits	Bin. Bits
TIME	Bank 1 (actual)	Bank 1 (specified) 
Marker	STAMP 
0.28	0.75	1 
0.59	0.75	1 
0.88	0.75	1 
1.19	0.75	1 
1.49	0.75	1 
1.79	0.75	1 
2.08	0.75	1 
2.39	0.75	1 
2.69	0.75	1 
2.99	0.75	1 
3.29	0.75	1 
3.59	0.75	1 
3.89	0.75	1 
4.18	0.75	1 
4.49	0.75	1 
4.78	0.75	1 
5.09	0.75	1 
5.39	0.75	1 
5.69	0.75	1 
5.98	0.75	1 
6.29	0.75	1 
6.58	0.75	1 
6.89	0.75	1 
7.19	0.75	1 
7.49	0.75	1 
7.78	0.75	1 
8.09	0.75	1 
8.39	0.75	1 
8.7	0.75	1 
8.99	0.75	1 
9.28	0.75	1 
9.59	0.75	1 
9.89	0.75	1 
10.19	0.75	1 
10.49	0.75	1 
10.78	0.75	1 
11.08	0.75	1 

*OXS in 01-04-032 for B1 S1*

Friday	18	May	2012	21:16:10:26610	VCDS Version: Release 11.11.3 (x64)
021 906 018 K MOTRONIC ME7.1 G V06 

Group A:	'032 
Adaptation (Idle)	Adaptation (Partial)	Bin. Bits	Bin. Bits
TIME	Bank 1 Sensor 1	Bank 1 Sensor 1 
Marker	STAMP % % 
0.01	-3.4	0 
0.3	-3.4	0 
0.6	-3.4	0 
0.9	-3.4	0 
1.2	-3.4	0 
1.49	-3.4	0 
1.8	-3.4	0 
2.1	-3.4	0 
2.39	-3.4	0 
2.7	-3.4	0 
2.99	-3.4	0 
3.3	-3.4	0 
3.59	-3.4	0 
3.9	-3.4	0 
4.2	-3.4	0 
4.5	-3.4	0 
4.8	-3.4	0 
5.09	-3.4	0 
5.4	-3.4	0 
5.7	-3.4	0 
5.99	-3.4	0 
6.29	-3.4	0 
6.6	-3.4	0 
6.9	-3.4	0 
7.2	-3.4	0 
7.5	-3.4	0 
7.79	-3.4	0 
8.09	-3.4	0 
8.4	-3.4	0 
8.7	-3.4	0 
9	-3.4	0 
9.29	-3.4	0 
9.6	-3.4	0 
9.9	-3.4	0 
10.2	-3.4	0 
10.49	-3.4	0 
10.8	-3.4	0 
11.09	-3.4	0


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## 7rrivera7 (Jun 24, 2010)

Ok, I just saw and email from Jack stating I did not run the test properly - sorry. I will repost...


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## 7rrivera7 (Jun 24, 2010)

Reposting *OXS in 01-04-034 for B1 S1* as I did not activate the test previously. 031 and 034 remained the same so I won't repost those.

021 906 018 K MOTRONIC ME7.1 G V06 

Group A:	'034 Group B:
Engine Speed	Catalytic Converter	Dynamic Factor	Result	
TIME	(G28)	Bank 1 Temp.	Bank 1 Sensor 1	Lambda Aging	TIME
Marker	STAMP /min	°C STAMP
0.01	760	165	0.797	B1-S1 Not OK	
0.3	760	165	0.797	B1-S1 Not OK	
0.59	760	170	0.797	B1-S1 Not OK	
0.89	760	170	0.797	B1-S1 Not OK	
1.18	800	170	0.797	B1-S1 Not OK	
1.48	800	170	0.797	B1-S1 Not OK	
1.79	800	170	0.797	B1-S1 Not OK	
2.09	760	170	0.797	B1-S1 Not OK	
2.39	760	170	0.797	B1-S1 Not OK	
2.69	840	170	0.797	B1-S1 Not OK	
2.99	1000	175	0.797	B1-S1 Not OK	
3.29	1160	175	0.797	B1-S1 Not OK	
3.59	1200	180	0.797	B1-S1 Not OK	
3.89	1280	180	0.797	B1-S1 Not OK	
4.19	1320	180	0.797	B1-S1 Not OK	
4.49	1360	180	0.797	B1-S1 Not OK	
4.78	1280	180	0.797	B1-S1 Not OK	
5.09	1200	180	0.797	B1-S1 Not OK	
5.39	1120	180	0.797	B1-S1 Not OK	
5.68	1040	180	0.797	B1-S1 Not OK	
5.99	960	180	0.797	B1-S1 Not OK	
6.29	920	180	0.797	B1-S1 Not OK	
6.59	880	180	0.797	B1-S1 Not OK	
6.89	800	180	0.797	B1-S1 Not OK	
7.18	800	180	0.797	B1-S1 Not OK	
7.49	800	180	0.797	B1-S1 Not OK	
7.79	840	180	0.797	B1-S1 Not OK	
8.09	960	180	0.797	B1-S1 Not OK	
8.39	1160	185	0.797	B1-S1 Not OK	
8.69	1280	185	0.797	B1-S1 Not OK	
8.99	1360	190	0.797	B1-S1 Not OK	
9.29	1400	190	0.797	B1-S1 Not OK	
9.59	1360	190	0.797	B1-S1 Not OK	
9.89	1320	190	0.797	B1-S1 Not OK	
10.19	1320	190	0.797	B1-S1 Not OK	
10.49	1160	190	0.797	B1-S1 Not OK	
10.79	1080	190	0.797	B1-S1 Not OK	
11.09	960	190	0.797	B1-S1 Not OK	
11.38	840	185	0.797	B1-S1 Not OK	
11.69	800	185	0.797	B1-S1 Not OK	
11.99	760	185	0.797	B1-S1 Not OK	
12.29	720	185	0.797	B1-S1 Not OK	
12.58	760	185	0.797	B1-S1 Not OK	
12.89	800	185	0.797	B1-S1 Not OK	
13.18	840	190	0.797	B1-S1 Not OK	
13.49	1000	190	0.797	B1-S1 Not OK	
13.79	1320	195	0.797	B1-S1 Not OK	
14.09	1640	200	0.797	B1-S1 Not OK	
14.39	1800	205	0.797	B1-S1 Not OK	
14.69	1480	200	0.797	B1-S1 Not OK	
14.99	1320	200	0.797	B1-S1 Not OK	
15.29	1200	200	0.797	B1-S1 Not OK	
15.57	1040	200	0.797	B1-S1 Not OK	
15.89	960	200	0.797	B1-S1 Not OK	
16.19	840	195	0.797	B1-S1 Not OK	
16.49	800	195	0.797	B1-S1 Not OK	
16.79	880	195	0.797	B1-S1 Not OK	
17.08	1040	200	0.797	B1-S1 Not OK	
17.38	1280	205	0.797	B1-S1 Not OK	
17.68	1480	205	0.797	B1-S1 Not OK	
17.98	1720	215	0.797	B1-S1 Not OK	
18.28	1920	215	0.797	B1-S1 Not OK	
18.58	2000	220	0.797	B1-S1 Not OK	
18.89	1880	220	0.797	B1-S1 Not OK	
19.18	1600	215	0.797	B1-S1 Not OK	
19.48	1360	215	0.797	B1-S1 Not OK	
19.78	1160	210	0.797	B1-S1 Not OK	
20.08	1040	210	0.797	B1-S1 Not OK	
20.37	960	210	0.797	B1-S1 Not OK	
20.68	880	210	0.797	B1-S1 Not OK	
20.98	840	210	0.797	B1-S1 Not OK	
21.27	760	205	0.797	B1-S1 Not OK	
21.58	720	205	0.797	B1-S1 Not OK	
21.87	760	205	0.797	B1-S1 Not OK	
22.18	760	205	0.797	B1-S1 Not OK	
22.47	760	205	0.797	B1-S1 Not OK	
22.77	720	205	0.797	B1-S1 Not OK	
23.08	760	200	0.797	B1-S1 Not OK	
23.37	760	200	0.797	B1-S1 Not OK	
23.68	720	200	0.797	B1-S1 Not OK	
23.97	720	200	0.797	B1-S1 Not OK	
24.28	720	200	0.797	B1-S1 Not OK	
24.57	720	200	0.797	B1-S1 Not OK	
24.88	760	200	0.797	B1-S1 Not OK	
25.17	760	200	0.797	B1-S1 Not OK


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## 7rrivera7 (Jun 24, 2010)

Ok, so while I wait for a response, I decided to trace the wiring from the O2 harness connector to the ECM. After studying the Bosch LSU and Bentley wiring diagrams, I figured out the BLACK wire on the LSU (VS) is the signal to the ECM. This wire goes to the GREEN wire on the O2 harness which leads to PIN 70 on the ECM. I pulled out my multi-meter and validated continuity to PIN 70 on the ECM.

My troubleshooting leads me to beleive the O2 circuitry on the ECM has been compromised, most likely due to the original O2 sensor wiring which was frayed.

Before looking for a replacement ECM, I am going to remove it and trace O2 input pin 70 into the main board to see if I find any burnt, open or out of range components.

I will report back...


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## 7rrivera7 (Jun 24, 2010)

Ok, while attempting to open the ECM, I noticed it is weather sealed so I've decided to leave it along and not break said seal. I found one on Ebay for $99 so I'm covered.

Before buying the ECM, I'm going to make sure my O2 sensor is actually SENDING a signal to it even though it is new - you never know.

...I'll report back


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## 7rrivera7 (Jun 24, 2010)

I back probed the O2 sensor for voltage on the GREEN wire which is the input tp the ECM on pin 70 and it stays at a constant 2.4v.

The testing procedure I have says after the car is in closed loop, the voltage should fluctuate above and below .45 volts but it's not happening. The car has been idling for over 20 minutes and for 1 of those minutes , I held the revs at 3000 trying to force closed loop.

The car is at temperature (190) but I don't see anything from the sensor. Could the new sensor be bad? Am I tested correctly?

Please help!

Here is the O2 sensor wiring diagram I am using:

http://wbo2.com/cable/lsuconns.htm


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## stan067 (Feb 25, 2010)

O2 Pin 1 Green to pin 70 ECU 
O2 Pin 2 Black to pin 71 ECU
O2 Pin 3 Blue/Yellow to fuse 43 10 amp side of dash. Has power when fuel pump runs.
O2 Pin 4 White to ECU pin 5
O2 Pin 5 Orange/ Purple to ECU pin 51
O2 Pin 6 Orange/Brown to ECU pin 52

I like ohm check the wires and load test with both O2 & ECU disconnected.

Follow these on your Bentley to learn how to read a track wiring diagram. Believe me I know how different V.W. track wiring diagram can be. Takes a lot of practice. 

Good Luck


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## 7rrivera7 (Jun 24, 2010)

stan067 said:


> I like ohm check the wires and load test with both O2 & ECU disconnected.


Wow Stan thanks for that info - it'll definately help me learn the wiring diagrams and help me test the rest of the O2 wiring for continuity into the ECM :thumbup:

What can you tell me about the O2 sensor? Am I testing correctly by monitoring the GREEN wiring for a crossover voltage?

I just realized the Innovative wideband on my drag Civic uses the same O2 sensor so I'll be swapping it in today to see if works any different from the one currently installed on the Jetta.

I quoted you on the ohm check and load testing. Ohm checking is continuity right? What exactly is load testing and how do I do that?

Thanks again buddy!


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## stan067 (Feb 25, 2010)

Disconnect the ECU & the O2.
With a DVOM meter put one end in pin 1 of O2 connector and the other in pin 70 of the ECU. Set meter to ohm’s and you should have less then .5 ohm’s ½ an ohm. This is the amount of resistance in the wire. Less is better more is bad.

Load test is actually putting power on the wire at one end and go to the other end with a test light to see if the light lights. You are actually running power thru the wire to test it.
The load is the amount your test light takes to light up. 
Most test lights don’t have much of a load so this would be a low load test. 
If you take an old head light bulb and connect wires to the light and make a test light with a headlight bulb this will draw a few amps (more power). 
A test light draws very little power like a flash light bulb so it’s not a good load tester.
The head light bulb draws a lot more power to light more then is needed for O2 & ECU circuit. 
So if each wire lights up a head light bulb you know it can carry a load. “Load test”
Don’t leave the head light bulb on for a long time it gets hot and if it draws too much currant for the size of the wire it will get hot and melt. And these are small wires just light them for a few seconds and you are done and know 100% the wire is good and can carry a load of a few amps. Which is more power then the circuit will ever need.

I don’t like the idea of swapping O2 sensors with another type of car! Unless you really know what you are doing and you don’t. LOL

Post the part # of the new O2 sensor and where you got it?

If the O2 is good and the wiring is load tested then I’d start to think ECU is bad.

That’s it for your basic electricity class…

Good Luck


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## 7rrivera7 (Jun 24, 2010)

Thank you Stan!

...actually, I know a lot more than you think but that's not important right now 

I tested continuity on the 5 sensor wires to the ECM and fuse #43 and they checked out good and since I was anxious to swap the O2 sensor, I decided to perform the ohm and load tests later.

I swapped the sensor with a spare I have from my Innovative Wideband controller which I use to tune my drag Civic. I've got 3 used and 1 new sensor and it is exactly the same one used on the Jetta - Bosch LSU-4.2 #17014 (0 258 007 057), VW part #021-906-262B.

I performed a Free-Air calibration on one of the spare sensors to make sure it was working and plugged it into the Jetta's pre-cat bung...

I got the same code 

I decided to run the following tests with VCDS:

*1) Block 030: Oxygen Sensor Regulation*

I can see the alternating heater on / heater off so this test passed

*2) Block 032: Oxygen Sensor Control Learned Values*

Value should be somewhere between -10 and +10%. My value is -2.3% so this test also passed

*3) Block 033: Pre-Cat Oxygen Sensor Control*

Value should fluctuate at least 2% in the -10 to +10% range. My value is 0.0% - FAILED

*4) Block 036: Post-Cat Oxygen Sensor Control*

Ran the test by depressing the brake pedal, the RPMs rose to 1400, the field 1 voltage fluctuated between .45 and .50v and the test ended with B1-S2 OK. This was expected as I've never gotten a code for the post-cat sensor.

*5) Block 034: Aging of the Pre-Cat Oxygen Sensor*

This test is similar to the Block 036 test procedure-wise. The "aging value" must be above 0.80 and my value stayed a 0 and the test ended with "B1-S1 NOT OK"

I also decided to test my cat using *Block 046*. The value should be below 0.50 and my value was 0.35 which means my cat is "efficient". The test never completed though but I think it's due to my failing pre-cat O2 sensor.

My troubleshooting process, which I have outlined here for the benefit of others dealing with this issue, leads me to believe my ECM has a failing O2 sensor control circuitry which was most likely caused by the original O2 sensor with frayed touching wires that was installed when I bought the car.

I still have to ohm and load test the O2 harness and will be doing that next before purchasing a ECM.


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## 7rrivera7 (Jun 24, 2010)

Ohm tested the O2 harness wiring and got between .5 and .6 ohms on all the wires - PASSED.

Not sure if load testing is necessary at this point...


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## stan067 (Feb 25, 2010)

You are correct you know more then I thought. Didn’t mean anything by it!

V.W. wiring is weak so I load test! Your time, your money, your car, your call…

Your theory is sound and possible about the ECU.

1.8 T motors loose throttle control from the ECU pedal controls when the O2 wires short to heater circuit. Known problem!

If your wires are good get an ECU next step.

Block 032 field 1 & 2 at idle and part load. Is LTFT at idle and at load given twice.
You only gave the value of 1 field and didn’t say was it idle or part?
What’s field 1
What’s field 2

Clearing codes resets the O2 setting for LTFT so check them after a long run.
But I would clear all codes and watch block 001 for fuel control.
If you have a code ECU will default stuff. Once the code sets I don’t trust the data.

Good Luck


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## 7rrivera7 (Jun 24, 2010)

Load test passed - time for a new ECU.

I'll report back when I get it installed...

Thanks to both Jack and Stan for your help with this :thumbup:


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## [email protected] Parts (Nov 27, 2006)

THIS POST MOVED/VACATED BY JACK TO PROTECT CONTENT FALLING INTO THE GAPING HOLE OF THE VORTEX

IT SEEMS NO GOOD DEED GOES UNPUNISHED!

http://www.youtube.com/watch?v=HaoySOGlZ_U


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## 7rrivera7 (Jun 24, 2010)

[email protected] Parts said:


> I can test that ecu if you want just to verify and also apply a core credit if you need one.
> 
> Is the MAF OE or China land?
> 
> Add fuses for that OXS heater circuit.


I already purchased an OEM ECM on Ebay for $115 shipped.

The MAF is an OEM replacement also purchased on Ebay for $35 shipped. I got lucky on that one because the seller never mentioned OEM on his auction and I found out via pre-purchase messages. There is a lot of China garbage on Ebay though so buyer beware.

Fuses on the heater circuit would be in-line, possibly tucked under the chassis right near the sensors right?


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## [email protected] Parts (Nov 27, 2006)

THIS POST MOVED/VACATED BY JACK TO PROTECT CONTENT FALLING INTO THE GAPING HOLE OF THE VORTEX

IT SEEMS NO GOOD DEED GOES UNPUNISHED!

http://www.youtube.com/watch?v=HaoySOGlZ_U


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## 7rrivera7 (Jun 24, 2010)

[email protected] Parts said:


> Yup that's a good place.
> 
> Hope that MAF works out.
> 
> ...


Holy sheit! Immobilizer? I'm a n00b!

My main concern was the part number on the ECM and I totally forgot about the IMMO although I have read about it in the past.

Can you give me more details on the exact procedure for adapting the new ECM. I should have it by tomorrow and want to install it asap.

As far as the MAF, it did eliminate a code I had with the original - signal too high or something to that effect. I even put the old one back and the code came back so I know the replacement is good. I will run the MAF tests though as soon as I get the new ECU installed.

Thanks again Jack!


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## bearthebruce (Dec 23, 2005)

Much of the detail about Immobilizer is found in the Ross-Tech Wiki Immobilizer section.


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## stan067 (Feb 25, 2010)

Go here to figure out which immobilizer you have.

http://wiki.ross-tech.com/wiki/index.php/Immobilizer

If it immobilizer 1 or 2 you can do it. If it 3 as jack said.

Good Luck


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## 7rrivera7 (Jun 24, 2010)

Thanks guys - this forum is great!


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## [email protected] Parts (Nov 27, 2006)

No problem 

Let me know if I can be of assistance.


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## 7rrivera7 (Jun 24, 2010)

Update: 

Received and installed the replacement ECM, followed the instructions in the WIKI and after waiting 15 secs, I started her up... 

The hesitation and terrible idle seems to be gone but I've got a slew of new codes I'm assuming have to be cleared (clearing DTCs after swappping the ECM is not part of the WIKI instructions but since I'm a n00b, this is probably common sense). 

Ran another FULL SCAN and I have no codes except for one on the Auto Trans Module - System not ready for interrogation, (Ross-tech try later). 

I'm not going to claim victory yet. I shut off the car and I'm going to let it sit for half an hour then run another FS and report back


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## 7rrivera7 (Jun 24, 2010)

Victory! 

VCDS is the bomb and this forum is my salvation - at least for the Jetta  

Opinions and reputable shops on repairing the original ECM? Is it worth it to invest and have as a spare?


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## stan067 (Feb 25, 2010)

Is the ECU programed for a standard trans or automatic? 
Older ECU's could be used for either you just had to program it for what you had in the car. 
Whats the coding string or coding #? 
Do you have a separate TCU trans computer or is the ECU the only computer under the wipers. 

I think the used unit is from a std. and you have an auto trans. 
good luck


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## 7rrivera7 (Jun 24, 2010)

stan067 said:


> Is the ECU programed for a standard trans or automatic?
> 
> *Auto*
> 
> ...


 
Thanks Stan!


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## stan067 (Feb 25, 2010)

So your fixed? 
what are the fuel trims group 032 field 1 & 2? 
Good Luck


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## 7rrivera7 (Jun 24, 2010)

Yea, I'm fixed! 

I checked 034 and ran the test and it passed with aging at 1.99 & B1-S1 OK. 1.99 means new sensor which it is. 

You still want to know the trims? Don't I have to run the car on the road for awhile for the trims to age?


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## GohanBurner (Jun 10, 2011)

I just got my O2 sensors replaced yesterday and the P0134 code came right back after a clear. Have never replaced the MAF or checked the coilpack for arcs. Would either of those trip that code for no activity b1s1?

Sent from my Galaxy Nexus using Tapatalk 2


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## stan067 (Feb 25, 2010)

Need an auto scan or start a new thread. 
Good Luck


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## GohanBurner (Jun 10, 2011)

How do I get an auto scan? 

Sent from my Galaxy Nexus using Tapatalk 2


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## stan067 (Feb 25, 2010)

You need to own VCDS.
This is the VCDS forum.
Watch the video on how to do an auto scan.

http://www.youtube.com/watch?v=4jt3lYLy4UU

Good Luck


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