Abs and ESP problems

E

edvarda2

Member
Hi!
I have a problem with my newly bought 2001 A2 1,4. By the way, incredible that this car is 15 years old. Looks almost as new, both condition and design. But OK. When starting, eveything is fine. After some minutes, the EPC and ABS warning lights, alarm and warning in center lights up. At that exact time, the engine seems to do a small cough, and after this seems to have a small power loss or ignition break in the mid rev area. I notice that the steering wheel is not perfectly straight. But maybe only 2-4 cm off center. Apart from this, everything is fine. Audi mecs have searched computer without error codes or result. Maybe an ABS/ESP sensor fault?
 
edvarda2 said:
Hi!
I have a problem with my newly bought 2001 A2 1,4. By the way, incredible that this car is 15 years old. Looks almost as new, both condition and design. But OK. When starting, eveything is fine. After some minutes, the EPC and ABS warning lights, alarm and warning in center lights up. At that exact time, the engine seems to do a small cough, and after this seems to have a small power loss or ignition break in the mid rev area. I notice that the steering wheel is not perfectly straight. But maybe only 2-4 cm off center. Apart from this, everything is fine. Audi mecs have searched computer without error codes or result. Maybe an ABS/ESP sensor fault?
Click to expand...

If it is an ABS / ESP fault then there will be error codes stored.

Are these Audi dealer mechanics or independent?

It could be anything, but the ABS and ESP would not affect the engine running at all, that may be a separate fault.

Your brake lights are working correctly aren't they??

Steve B
 
the off center is a massive issue. Get it fixed first; but read the error messages to find out what the true error is. Off center means that when you try to apply power, it won't happen and the computer starts to think the EDS needs to be used (because the wheel is tilted but the car is not rotating). It might be a suspension issue, it might not be.

I've had this before when one of the front wishbones was not bolted in 100% and I had the wheel at around 10 degrees. THe car refused to accelerate at some point because it was sure EDS was needed.

- Bret
 
Thanks for extremely quick replies! No error codes are stored, according to previous owner. Mechanic was Audi guy. Maybe my description of engine power loss is wrong. It could have been a slight abs/esp-initiated braking sequence, interpreted by me as a power loss/engine problem. Havent checked the brake lights, will do. What would that imply? Prev owner says the problem have come and gone now and then. The car is in very good shape, prev owner just EU certified it by spending approx 20.000 Nok, 2500 usd. Suspension was fully changed, and other things.
 
The brake lights thing is just clutching at straws.

If the brake switch goes or if both brake light bulbs fail, the system thinks the car is slowing down without any braking being applied and it throws up several flashing icons, ABS, EML and flashing preheater symbol for a start.

The switch normally starts to operate intermittently towards the end of its life and so it is not always spotted.

It sounds far more like an ABS sensor, or lateral force sensor (yaw sensor) or similar, BUT these all throw up error codes when they fail.

If he didn't have the full diagnostic kit or a genuine VCDS cable that might explain why he didn't pick up any codes?

Steve B
 
Get the codes read, the illumination of those lights does not necessarily mean it's anything to do with ABS or ESP.

If you turn the ignition off and on again, do the lights disappear?
 
The mech checking was an authorised Audi shop. No codes. The car is just EU certified, brake lights are working fine. Maybe the wiring to the abs sensor? Recently a lot has been changed at the car, brakes, wheel bearing and suspension. Maybe the mechs have touched something by accident. Where is the yawsensor located?
 
edvarda2 said:
Suspension was fully changed, and other things.
Click to expand...

this is your problem. The front subframe / axle may not be in the correct place.

Really important: ASR will flicker a light on the dash. EDS will not. It feels a little like a hiccup (most unnerving when you're trying to overtake) but that's what happens.

The yaw sensor is under the gearstick.

Test: pull fuse 40 and see what happens, but be careful. That's ABS / EDS / ESP.

And don't believe there are no error codes, not everything is shown on the dash....

Trust, but verify.

- Bret
 
Will speak to the Audi mec, and test the fuse. Anyway, visual check of sensors and wiring should be easy. Also wheel angle adjustment, at least to a 90-95 % level is relatively easy. Problem has come and gone for a couple of years, according to prev owner. During that time, the car has had a lot of repairs, wheel bearings, brakes, suspension and some sensors/electronics. The problem was there before this, have disappeared and appeared again. It might come from more than one source. Thanks anyway guys, for extremely quick and qualified diagnostics (and guessing...). I will update with results.
 
Now Ive spoken to Audi mec. He says the problem sits in the motor control unit. This is coded with tolerances that my cars various sensors cant match due to wear and tear. Furthermore, he says the car goes into emergency mode, and the exact reason varies. In his opinion, the only solution is changing the control unit for a new one, and coding this with other tolerances. This operation is not possible in the existing control unit. I dont accept his explanation nor solution. The car looks almost like new, both mechanically and cosmethic.
 
If front wheel bearings have been changed, the first thing I would check would be the ABS sensors.

RAB
 
an alignment check is also to be recommended. Maybe you want to get a ferry to Kiel and find someone who really understands the car?

- Bret
 
Before anything else, I'd do a full diagnostic check. Note and clear every code and see which ones return before you start taking anything apart.
 
Philip said:
Before anything else, I'd do a full diagnostic check. Note and clear every code and see which ones return before you start taking anything apart.
Click to expand...
The OP had confirmed that no error codes are listed when the car was scanned by an Audi mechanic. I too believe that this surely can't be true. But what can the OP do?

if any member with VCDS is close then perhaps they might offer s scan.
ABS type problems would almost always trigger an error.

Steve B
 
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