# Traction control and ABS light issues



## gls:maverick (Oct 18, 2005)

So just about everyday on my way home from work about 20min in with everything up to temp. My ABS light and my Traction Control light both come on and stay on until I shut the car down for more than a few minutes. While on the car seems to run and brake fine. In the current snowy conditions I don't seem to have a loss of traction in the rear but I don't feel the rears engage in snow like I normally do. So are the rears always on in this situation? 
Either way I would like to figure out this issue and any help would be awesome. Maybe wheel speed sensor or the ring that it reads?


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## A4 1.8 Turbo (Feb 28, 2005)

*Re: Traction control and ABS light issues (gls:maverick)*

It could be either wheels speed sensors or the longitudinal speed senor, which is burried behind the dash on the passenger side. When the abs light is on, vag the car. it'll tell you whats acting up.


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## gls:maverick (Oct 18, 2005)

*Re: Traction control and ABS light issues (gls:maverick)*

Just an update....it luckily happened today on a really smooth spot of road. The car actually (very, very slightly) jerked back when the lights came on


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## A4 1.8 Turbo (Feb 28, 2005)

*Re: Traction control and ABS light issues (gls:maverick)*

are you feeling anything in the pedals? Usually when this happens, your abs will be engaging every time you brake. Did you get a chance to scan it yet?


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## bauch1425 (Jun 29, 2006)

*Re: Traction control and ABS light issues (A4 1.8 Turbo)*

The two lights on together is usually either the longitudinal/latitudinal sensors related to the stability control system, which shouldn't engage your ABS... you need to VAG-Com it and get a code.
My car has had this issue for months now... not really a high priority in my book to fix as on top of the longitudinal sensor (ESP and ABS lights on), the steering angle sensor is also bad (only the ESP light comes on when this one "decides" to fail).


_Modified by bauch1425 at 2:09 PM 2-23-2010_


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## A4 1.8 Turbo (Feb 28, 2005)

*Re: Traction control and ABS light issues (bauch1425)*

i think the sensors are like 130 each or so...
In the mean time this info stolen from AW may help you out:
Throwing code 
01279 - Longitudinal Acceleration Sensor (G251)
27-10 - Implausible Signal - Intermittent
for the past few weeks, ABS and ESP lights come on in cluster. Dealer replaced today under CPO warranty ($50). It was P/N 1J0 907 651 A and was located behind the glove box as shown in pic below. Be aware, searching this topic reveals conflicting advice, looks like the sensors are in different locations depending on model year. According to my dealer tech, and the Bentley manual, here are the locations for this sensor:
Longitudinal Acceleration Sensor (G251) Through model year 2002 (this is where it was on my 2001):










_Modified by A4 1.8 Turbo at 5:28 PM 2/23/2010_


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## gls:maverick (Oct 18, 2005)

*Re: Traction control and ABS light issues (gls:maverick)*

I do not feel any change in the pedal and the ABS is certainly not controlling my braking (non of that "ABS" shutter when coming to a stop). I havent tried locking the brakes up yet though; I suppose today while the light is on I will find a somewhat vacant parking lot and lock em up and see what happens.
Also I havent scanned anything because I dont have VAG Com and the closes shop with one is like 40min away or more depending on traffic.


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## cdougyfresh (Sep 16, 2004)

*Re: Traction control and ABS light issues (A4 1.8 Turbo)*

I have the same issue, and also am throwing code 01279 - Longitudinal Acceleration Sensor (G251)
Good info http://****************.com/smile/emthup.gif 
Another item on the to do list, but as previously stated im not in a huge hurry to fix it


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## A4 1.8 Turbo (Feb 28, 2005)

*Re: Traction control and ABS light issues (cdougyfresh)*

I had that code on my old 180Q that i sold, but it was intermittent. Some days it would come on, then sometimes it wouldnt come on for weeks. But it was always a code for sensor # G251. I just left it alone. I can deal with the ABS light, But the cel on the other hand, that one just burns my retna's when it's illuminated.


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## cdougyfresh (Sep 16, 2004)

*Re: Traction control and ABS light issues (A4 1.8 Turbo)*

yeah mine is verrry intermittent, i would estimate it comes on maybe 2-3 times a week, always goes away if car is turned off & restarted.


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## A4 1.8 Turbo (Feb 28, 2005)

*Re: Traction control and ABS light issues (cdougyfresh)*


_Quote, originally posted by *cdougyfresh* »_ always goes away if car is turned off & restarted. 

They will....Everytime you start driving the car, It does a 32 mph check of the system. If during your first hundred yards of driving you peak above 32 mph and don't touch the brakes it'll probably stay off. if you hit the brakes or accellerate hard it will more likely come on. On the other hand if it detect's an intermittent signal loss or spike, it will trip the abs light.


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## Malant (Aug 30, 2004)

*Re: Traction control and ABS light issues (A4 1.8 Turbo)*


_Quote, originally posted by *A4 1.8 Turbo* »_
They will....Everytime you start driving the car, It does a 32 mph check of the system. If during your first hundred yards of driving you peak above 32 mph and don't touch the brakes it'll probably stay off. if you hit the brakes or accellerate hard it will more likely come on. On the other hand if it detect's an intermittent signal loss or spike, it will trip the abs light. 

Good to know, I have been trying to diagnose what causes mine to come on however most times it has just been random.
If you don't mind me asking (I am not discrediting you, just been doing a lot of research on this and have came up with next to nothing), where did you find this information?
-John


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## A4 1.8 Turbo (Feb 28, 2005)

*Re: Traction control and ABS light issues (Malant)*

Various trips to the audi dealership, and lots and lots of google, And there is this 25 sumthin odd page pdf I found about haldex......
http://www.vaglinks.com/Docs/A...e.pdf
tells you all about how all the different systems like haldex, abs, wheels speed sensors, longitudinal sensors and all that play into our tt's. Its a great read if you have some spare time. 
Page 9 of the document is where it shows the interlacing of the sensors. 


_Modified by A4 1.8 Turbo at 7:30 PM 2/24/2010_


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## Nmarquis (Jan 30, 2012)

Could any of this be attributed to aftermarket wheels and tires by chance?
I had this happen to me, and when the lights came on I no longer had abs or traction control.


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## TommyTT (Jul 10, 2012)

I've been having this exact same issue!

I noticed that when I punched it hard is when both lights would come on, I have never had only 1 light come on. I asked a friend whom worked for Audi, past tense... he suggested a MAF sensor, that didn't do anything. Though my lights are a lot less frequent now... He also mentioned a fuse block on the passenger area of the vehicle that gets corrosion on some.

Sadly, I have not been able to get the lights on when my friend with vag-com is available so I haven't code checked yet which is the next step.

I don't think wheel setup has anything to do with this as I'm running my 205/50R16 winter steelies!


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