# Audi TT, vehicle speed sensor



## toomuchtoplaywith (Dec 21, 2006)

Immediately after doing my boost gauge install and haldex service, the speedo on my TT quit working(dont know if anything is related)
I am using a dealer VAG 1551, so I do not have the means to copy/paste my diagnostic results on the computer
I have a 2001, Audi TT 225 Quattro, 1.8t AMU motor 
date of production 09/00
I have a CEL, in01 Engine Electronics, comes up as: 16885 Vehicle Speed Sensor Range/Performance
My speedo does not function while driving, and the milage on my odometer does not change. 
I have checked Measured value blocks, and: all 4 wheel speed sensors are showing the same speeds while moving(seems to be correct).
I also ran the diagnostic test mode on my IP Cluster, and the speedo gauge "sweeps" properly, and in sync with the Tach.
Other mods: I have coilover suspension and sway bars, that have been installed for over a year.
The fuel gauge and display on my cluster already acted funny, which would lead me to belive that my speedo finally shot craps as well. However..... it does function properly when using the output diagnostic test mode. The DTC gave me no "J" or "G" number indicating a faulty part either(such as J279). 
Any help is definitely appreciated! Thanks 
_Modified by toomuchtoplaywith at 12:08 AM 8/24/2007_


_Modified by toomuchtoplaywith at 12:09 AM 8/24/2007_


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## bearthebruce (Dec 23, 2005)

*Re: Audi TT, vehicle speed sensor (toomuchtoplaywith)*

My guess is that you have a loose connection that was disturbed by the install of your new gear. I'd take it apart and check it all.


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## Krissrock (Sep 10, 2005)

wow..what luck, I developed the same problem yesterday(with the same exact car). My entire cluster was replace maybe a year ago...and I had boost controller installed which needed to tap the speed wire behind the dash. Then speedo went kaput. No gas/mileage reading and gas (which was working fine) now constantly twitches....Would say it's the same thing, a loose connectiong somewhere?


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## toomuchtoplaywith (Dec 21, 2006)

I just ran my vacuumline through the firewall. I grounded the LED on a common ground under the dash, and tapped power from the dimmer for my headlights. I will take it back apart, and see if I can find anything, but I looked pretty well right when it started doing it, and didnt see anything.
NOTE: My ip cluster never came out of the car


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## toomuchtoplaywith (Dec 21, 2006)

So... I pulled out my boost guage, nothing looked out of the ordinary. Then I dropped my panel under my steering column, and completely disconnected the LED for my boost gauge, and nothing changed.
HELP!!!! Can someone tell me where my "Vehicle Speed Sensor" is?
That is the DTC I am getting. Through numerous Google searches, I can not find anything related to the location. I was under the impression that vehicle speed was determined by readings from ABS sensors(all 4). Is there a "sensor" in the IP cluster that interprets these readings and changes the speedo?
By the way, I went ahead and pulled my cluster, to check connections and get a part number, and I found the date 05/23/03... Meaning that my 2001(prod, date 09/00) has already had the IP cluster replaced.


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## Krissrock (Sep 10, 2005)

yeah i have a new cluster as well and my speed is gone. I saw on a page that the speed sensor is in the front near the oil filter...i'll see if I can find the page and post it cause i'm gonna try to replace mine before sending out my cluster....Do you have good instructions on removing the dash...cause when I removed mine it scracted up the steering colum...?


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## RMILLER (Nov 24, 2004)

*Re: Audi TT, vehicle speed sensor (toomuchtoplaywith)*

This is from Bentley...
Audi > TT > 2000 - 2005
1.8 Liter 4-Cyl. 5V Turbo Generic Scan Tool Engine Code(s): AMU, BEA, ATC, AWP
24 - Multiport Fuel Injection (MFI)Speed signal, checking Recommended special tools and equipment 
VAG1526 multimeter or VAG1715 multimeter 
VAG1594 connector test kit 
Wiring diagram 
Test requirements 
The respective fuses of Motronic Engine Control Module (ECM) -J220- must be OK: 
Battery voltage must be at least 11.5 volts. 
Speedometer -G21- must be OK. 
Test sequence 
Note: 
To test speed signal, vehicle must be driven. Doing this requires a second person. 
WARNING! 

Secure Scan Tool (ST) on the rear seat and have it operated from there by second technician. 
Connect diagnostic tester => page AUDI-TT-FU04-ST-001-03ST-7. 
Start engine and let run at idle. 
Under address word 33, select "Diagnostic mode 1: Checking measured values." 
Select the measuring value "PID 13: Vehicle speed". 
Perform a road test, and have the 2nd person observe the indication on the display. 
Check specified value of the vehicle speed: 
PID 
Diagnostic text 
Specified value: 

13:
Vehicle speed
approx. vehicle speed

End diagnosis and switch ignition off. 
If no speed is indicated: 
Connect test box to control module wiring harness => page AUDI-TT-FU04-ST-001-04ST-9, connect test box for wiring test. 
To measure voltage, connect multimeter between sockets 3 (terminal 15) +54 (speed signal) of test box. 
Jack up front left wheel. 
Switch ignition on. 
Rotate front wheel, and observe voltage indicated while doing so. 
Specified value: 0.0 to at least 4.0 V, fluctuating 
Note: 
The right front wheel must not turn during this, hold it steady if necessary. 
If indicated voltage does not oscillate: 
Remove instrument cluster: 
=> Repair Manual, Electrical Equipment, Repair Group 90, Instrument cluster, removing and installing 
Check wire connection from Engine Control Module (ECM) to Speedometer -G21- according to wiring diagram. 
=> Electrical Wiring Diagrams, Troubleshooting & Component Locations 
Erase DTC memory of Engine Control Module (ECM) => page AUDI-TT-FU04-ST-002-06ST-30, Diagnostic mode 4: Reset/erase diagnostic data. 
Generate readiness code => page AUDI-TT-FU04-ST-003-03ST-63. 
The processed signal enters at terminal 54 of the ECM and is used for idle stabilization and tip-in shock reduction during shifting.


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## toomuchtoplaywith (Dec 21, 2006)

*Re: Audi TT, vehicle speed sensor (RMILLER)*

I know I need to get that Bentley.
Iv basically already done the rolling test, watching the value blocks, and all of them show "proper speeds/readings".
I have also noticed, that even on light shifts (like at 2000 rpm), it feels like I shifted at 5500 from full throttle. And I just read something mentioned about shift-shock-reduction.
Ill get out my DMM, and test those voltages. Is that saying that the CLUSTER helps with the shift shock reduction?


_Modified by toomuchtoplaywith at 8:48 AM 8/26/2007_


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## Krissrock (Sep 10, 2005)

dude what is all that? how can you test that stuff with a vag-com? and is the speed measure from the left front wheel? I had my car on a dyno and maybe they knocked somethign off when they were strapping it down? what could I be looking for? so is that measuring block 33?


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## Krissrock (Sep 10, 2005)

i'm gonna check to see if anything looks outta place on my wheels, then follow this process replace the sensor if needed...
http://forums.audiworld.com/tt/msgs/1564604.phtml


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## toomuchtoplaywith (Dec 21, 2006)

*Re: (Krissrock)*

That sensor(by the oil filter) is the engine speed sensor. The code was thrown for the Vehicle speed sensor. 2 totally different things


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## Krissrock (Sep 10, 2005)

ohhh....so where is the vehicle speed sensor?


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## toomuchtoplaywith (Dec 21, 2006)

*Re: (Krissrock)*

Thats what Im tryin to figure out....but Iv got an idea.
You actually have 4 wheel speed sensors(1 on each wheel)... this is where things get a bit foggy!
I think the VSS interprets these signals, and gives an output to the speedo, therefore displaying the speed. I am kinda thinking it may be inside the IP Cluster. Mine has already been replaced once, but the fuel gauge and display are wackin out on it, maybe the speedo is now too.
I think Im just gonna take it ot the dealer, and have the cluster replaced. LAst Resort


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## Krissrock (Sep 10, 2005)

well, my gas isn't doing too well either, but when I had my speedo wire tapped for the EBC, that is when the speedo stopped working. But since the wire is tapped, if it was getting a signal at all, I think the EBC would get that signal and that would at least have a reading, but it isn't either. SO i'm assuming that nothing is coming through that wire...I'll try sending mine to that guy on the other thread and see what happens after that...


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## toomuchtoplaywith (Dec 21, 2006)

*Re: (Krissrock)*

I was gonna send it to him, but Im not 100% for sure he can fix whatever is screwy, I will ask to find out


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## M0E (Dec 29, 2006)

*Re: (toomuchtoplaywith)*

speedometer sensor should be on top of the diff


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## toomuchtoplaywith (Dec 21, 2006)

*Re: (M0E)*

I dont know exactly what I would be lookin for... do you have any pics or a diagram?
One thing that throws me off, is that usually, fault codes indicating a certain part, also give a number, like blahblahblah n75, or blahblahblah G235. You can usually call the dealer and say "i need a N75, and they can find the part". The code I get says VSS, range and performance..........nothing else. so im not sure if its indicating a part


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## Space9888 (Mar 18, 2002)

*Re: Audi TT, vehicle speed sensor (toomuchtoplaywith)*

i forgot to plug the speed sensor back in on my tranny, after doing a clutch job and it did the same exact thing. and the fuel light would come on sometimes when shifting gears. 
check to make sure the connector didnt pop off its not a hard thing to have happen as the connector merely pops on, and pops off very easily. 
i dont have a TT but the connectors are probably the same. 


_Modified by Space9888 at 4:42 PM 8-28-2007_


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## Krissrock (Sep 10, 2005)

....need more of a description...i'm not too familiar with things on the transmission...where is the diff?
I found this for a different car...close enough?
http://forums.vwvortex.com/zerothread?id=2703042


_Modified by Krissrock at 8:26 PM 8/28/2007_


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## toomuchtoplaywith (Dec 21, 2006)

*Re: (Krissrock)*

it SHOULD be the piece that your left front CV Axle bolts to. There cant be TOO many plugs on it.
I called the Audi dealer today, and they do have a "speed sendor" located on top of the diffrential. It was only like 50 bucks, so I figured its a cheap "try, and see if it works" before a $600 cluster n $200 install.


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## Krissrock (Sep 10, 2005)

ok, i'm gonna check it out this weekend. I hate taking any of my wheels off....


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## toomuchtoplaywith (Dec 21, 2006)

*Re: (Krissrock)*

If its on top of the diff, I would think you could pull the airbox, and it should be there. IDK, but Ill find out soon!


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## toomuchtoplaywith (Dec 21, 2006)

Alright... pulled the airbox, replaced the VSS... no dice... All symptoms are still the same


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## Krissrock (Sep 10, 2005)

awwe hella lame! !


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## toomuchtoplaywith (Dec 21, 2006)

*Re: (Krissrock)*

I think the cluster is the only thing left


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## Krissrock (Sep 10, 2005)

do you have, or could u take a pic of this sensor for me? i have P-Flow intake and I see down in there pretty good, but even when I take that off, I don't see any plugs....or anything unplugged. I emailed that guy on the other thread and he hasn't responded yet...


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## toomuchtoplaywith (Dec 21, 2006)

*Re: (Krissrock)*

take out yor airbox, look to the back of the diff, and you can barely see the plug. Its partially under your shift-cables
I found mine fully plugged in, replaced it anyway since I already bought the part


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## Krissrock (Sep 10, 2005)

the only thing I see is in front of the Diff...if I look straight down there's a plug...but you're saying it's near the back by the cables...i'll keep looking, but for some reason, I think you're right, and it's not the sensor. Shame no one else has experienced this before and has a solution....


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## toomuchtoplaywith (Dec 21, 2006)

Im must gonna schedule an appointment with the dealer this week to have them put a custer in.


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## toomuchtoplaywith (Dec 21, 2006)

*Re: (toomuchtoplaywith)*

I am an IDIOT!!! Rule #1 of electronics diag....always check ur fuses!!!















Check fuse 7(10a)... if its blown, replace it and ur speedo will work. Have autozone erase the DTC, and ur cruise will work.
You may also check fuses 5, 6, and 31
My speedo and cruise work perfect now


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## Krissrock (Sep 10, 2005)

hmm. i'll go check those now, cause i did check some fuses before...not sure if it was those numbers or not...I'll check them right now. I did make a few calls today, and one place asked me if I had any Abs lights. I said no. He said that it could be the sensor, or the DCS (i think that's what he said) He said that the speed signal goes through the DCS and then to the dash, or it could be the dash too...Then after giving me all the options, he said that he would pass on looking at my car lol. I can appreciate that...Lemme go check those fuses...


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## Krissrock (Sep 10, 2005)

*Re: (Krissrock)*

Sweet!! Dude, this is what the internet is for. Dissemination of information! I think I checked fuses regarding the dash, and that one is for the nav n ****...whatever. I'm just glad it's fixed. Thanks a lot cheers


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## toomuchtoplaywith (Dec 21, 2006)

glad we could be of help to eachother


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## Krissrock (Sep 10, 2005)

did you happen to notice any other symptoms when you dash went out?


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## toomuchtoplaywith (Dec 21, 2006)

*Re: (Krissrock)*

just speedo and cruise inop, trip/odometer not counting, and noticed the "shift shock" mentioned above, CEL on. 
I noticed when using the vag1551, wheel speed sensors for ABS worked, gauges worked on output diagnostic test mode, but in channel 33(obdII), it showed the vehicle was not moving.
Did you notice anything weird?


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## Krissrock (Sep 10, 2005)

*Re: (toomuchtoplaywith)*

well, mind you I had a boost and air fuel controller put in when the gauge went bad...but my main problem was a bucking when letting off the gas. I had put everything back to stock..(disconnected the controlling wires and actuator for the controllers) and I still had the bucking. When you let off the throttle, it would jerk forward, and I could hear something in the front kinda banging. I figured it was just my imagination, something tha was probably there before the install and gauge trouble. But, as soon as I got that fuse replaced....its all gone. Let off the throttle, and it's smooth as if I never let off it....
Another thing I noted was that my AFS select shows what correction is happening. It always read +4.0% no matter if I was moving or still. Now that I got the fuse replaced, the correction changes as I move or rev or the car...So I wonder if A/F setting change depending on whether it knows the car is moving or not....
But anyway, I just wanted to know if you had the lurching/bucking also


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## toomuchtoplaywith (Dec 21, 2006)

*Re: (Krissrock)*

I think the "bucking" ur describing, is the shift shock. The ecm uses the IP Cluster to help the shift shock. I felt it, not like it was gonna throw me through the windshield, but enough to be an annoyance


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## cruzanstx (Oct 10, 2011)

toomuchtoplaywith said:


> I am an IDIOT!!! Rule #1 of electronics diag....always check ur fuses!!!
> 
> 
> 
> ...


 very much a dead thread but saved me some serious $$, i never looked at the fuse. pulled it and sure enough 7(10a) was blown. same symptoms after aem uego afr install. Thanks much even from 5 years ago!


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## ttocsybles (Sep 7, 2006)

10 years later, and this post just saved me $100 on a speed sensor


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## vtraudt (Mar 1, 2010)

*2001 TT 225 AMU quattro 6 spd - no speedo*

No speedo.
Checked the cluster, steppers working.

https://drive.google.com/file/d/0B-F25jqwK4EwcEppZFhpay00djg/view?usp=sharing

Wheel speed sensors show signal in VAGcom.

Checked fuse 11 and 15 (on speedo and transmission related I could find, both 5A fuses) good. 

Can someone post the wiring diagram for the cluster? only found one diagram, but may not be applicable for our cars

http://forums.vwvortex.com/showthre...mp-Gauge-in-instrument-cluster-malfunctioning


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## vtraudt (Mar 1, 2010)

Going to check seemingly unrelated fuse 7 based on this from Dough at Frankenturbo:

"Upping this thread for its helpful information. Our TT test car had its speedo stop working suddenly. The gauge passed a VAG-COM output test "sweep" so it wasn't the cluster. Next, a voltage test of the wiring to the sensor showed no power going to it. So the sensor wasn't at fault. It boiled down to a fuse, no.7. I don't know why a fuse that's labeled for the "Back Up Lights" would affect this sensor, but it does. Here is the TT's fuse panel."



http://images36.fotki.com/v1159/photos/7/7305/776256/fusevi-vi.gif


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## vtraudt (Mar 1, 2010)

Checked fuse 7 also: good. 

Any good photos/schematic showing the location of the VSS on the tranny/transfer case/gearbox?


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## vtraudt (Mar 1, 2010)

vtraudt said:


> Checked fuse 7 also: good.
> 
> Any good photos/schematic showing the location of the VSS on the tranny/transfer case/gearbox?


Is the VSS shown next to the prop shaft flange at the rear of the tranny in this photo?


http://i1137.photobucket.com/albums/n510/grahams81/DSC00743.jpg


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