front shock replaced, now epc and traction light on

[robcarp1967]

hi guys

had my osf shock replaced by Audi on friday,,went to pickup my car on the friday, turned ignition on to find traction and epc light on the dash,which stayed on and wouldn,t go out ,went back into audi to explain and they,ve kept the car in for investigation,,any ideas,the fact that the shock has been replaced and now epc/traction light on, is there any link between the two,,the car was taken for a test drive by the tech after the shock replacement and apparently everything was fine,so inbetween the car being parked up and me picking it up now this problem has arisen,,

thanks for any input

[sonny]

The DRC is mechanical and in no way is associated to the EPC/TC

The ABS and Brake sensor wire could be damaged when taking the shock off but this still would not effect the EPC/TC

[eightfoot]

The DRC is mechanical and in no way is associated to the EPC/TC

The ABS and Brake sensor wire could be damaged when taking the shock off but this still would not effect the EPC/TC

arnt the top mount electricaly sensored

[adsgreen]

Nope. B7 drc is 100% me mechanical and damn clever and elegant.
I think that been part of te problem with the rs5/b 8 rs4 is making it adjustable you end up losing some of the focus. With it being fixed as in the b7 th engineers had to spend all of time fine tuning to make it 'just so'. With everything adjustable in big chunks it's much harder to make things all 'gel' together.

Surely they must have read the codes to fid out what the basic underlying cause is???
If I picked a car up from a dealer with a warning light showing I'd be damn insistent on getting it read.

TC + EPS iirc can often be the MAF sensor... Weird but true.

[robcarp1967]

thanks for all your inputs guys, audi still got my car they are going to look at it on tuesday,in the meantime they've give me a A5 cab 2.0 diesel courtsey,nice car, but i miss my RS

[bam_bam]

thanks for all your inputs guys, audi still got my car they are going to look at it on tuesday,in the meantime they've give me a A5 cab 2.0 diesel courtsey,nice car, but i miss my RS

I'm pretty sure DK took an A5 cab 2.0 diesel across Europe and hated it. Have fun with that.

[HYFR]

^^ yup

worst car I've EVER EVER EVER EVER EVER EVER EVER driven ... and I drove it for 9,000 miles

[adsgreen]

thanks for all your inputs guys, audi still got my car they are going to look at it on tuesday,in the meantime they've give me a A5 cab 2.0 diesel courtsey,nice car, but i miss my RS

Tuesday? Fecking Tuesday?!? How long does it take to plug diagnostics in and read the code.
If it is a maf sensor it's a ten minute job!

[ArthurPE]

I'm guessing wheel speed sensor
it's used by boith ABS and EPC/TC

ABS for obvious reasons, EPC/TC to sense a wheel spining to reduce torque

[adsgreen]

I'm guessing wheel speed sensor
it's used by boith ABS and EPC/TC

ABS for obvious reasons, EPC/TC to sense a wheel spining to reduce torque

But I would expect the ABS light to be on in that instance not TC and EPC.
We used to disable abs on track by unplugging a front sensor and immediately the ABS warning light would come on.

[bam_bam]

I'm guessing wheel speed sensor
it's used by boith ABS and EPC/TC

ABS for obvious reasons, EPC/TC to sense a wheel spining to reduce torque

But I would expect the ABS light to be on in that instance not TC and EPC.
We used to disable abs on track by unplugging a front sensor and immediately the ABS warning light would come on.

I've got my money with Arthur's prognosis. I'm trying to diag a similar issue on my C5. Pull the ABS controller and you lose TC control (no light but you can't switch off the TC) and the ABS light stuck on. Pulling a wheel sensor gives me both lights, go figure. With everything plugged in and then go on a long drive will give me both lights.
I'm not liking your theory on the MAF causing ABS issues, I don't need another variable right now, hence, I hate you... glad they're different cars.

[ArthurPE]

I'm guessing wheel speed sensor
it's used by boith ABS and EPC/TC

ABS for obvious reasons, EPC/TC to sense a wheel spining to reduce torque

But I would expect the ABS light to be on in that instance not TC and EPC.
We used to disable abs on track by unplugging a front sensor and immediately the ABS warning light would come on.

well if there is a correlation between the DRC and EPC, the only thing in the area is the wheel speed sensor(s)

the EPC/TC control is in the 2 main ECU's which are CAN (hi) Bussed with the ABS module
wheel speed is one parameter (others: module checks, over-rides, interventions, rough road signal, wheel speeds are 'bouncing', engine reduces torque a bit to smooth it out, among 10 others)

if the ABS wheel sensor fault cleared quickly (dirt, snow, whatever) the EPC may stay latched
I had ABS/EPC faults, the rear right wheel sensor connector was somehow dislodged when cleaning with a power washer
blew the water out, connnected it ABS cleared, EPC did not

if not the wheel sensors, just a coincidence and vagcom will point it out

[adsgreen]

No I do agree that given you'd think the only thing that could be disturbed with a drc change would be a speed sensor... just not immediately matching up to the indicated lights.
The bit I find really annoying is that this is trivial to diagnose with Vag Com - hell, the obvious thing to do is read the logs, store them and clear the codes and see what happens.

[bam_bam]

Logging is better but figuring out what to log is the tough part.

[adsgreen]

I'm guessing wheel speed sensor
it's used by boith ABS and EPC/TC

ABS for obvious reasons, EPC/TC to sense a wheel spining to reduce torque

But I would expect the ABS light to be on in that instance not TC and EPC.
We used to disable abs on track by unplugging a front sensor and immediately the ABS warning light would come on.

I've got my money with Arthur's prognosis. I'm trying to diag a similar issue on my C5. Pull the ABS controller and you lose TC control (no light but you can't switch off the TC) and the ABS light stuck on. Pulling a wheel sensor gives me both lights, go figure. With everything plugged in and then go on a long drive will give me both lights.
I'm not liking your theory on the MAF causing ABS issues, I don't need another variable right now, hence, I hate you... glad they're different cars.

I agree - the maf is a fecking weird one to trip the TC light but a dig through the achives says that its happened a couple times.
But not sure it causes ABS issues though.

Other cars I've worked on like Arthur says, the TC is not implemented in the ABS module. It uses the same sensors but the code for it is in the engine ECU. So unplugging the ABS module could mean the TC is still working or at least not throwing a code as it's getting the signals from the sensors (I'd need to check the wiring diagrams).
However unplugging the wheel sensor would screw up both TC and ABS modules up independently.
If you are getting both lights I'd be thinking either a sensor or the ABS controller is screwed - does vag com shed any light or point to a particular wheel?
(BTW - love you too )