slow motion curbed wheel now esp light is on intermittently

[chris fry]

Hi, through a momentary lapse of concentration i have managed to graze my rear alloy against a jaggedy curb, probably no more than 5mph, I wouldn't be too traumatized as they needed a refurb anyway, i'm more concerned the ESP light came on 20 miles after and stayed on for the rest of the journey, it went off and stayed off on restart, but has come back for short times over the last coupe of weeks. I presume i have disturbed the tracking rather than a sensor fault. Any advice or experience of the same? checked for fault codes and none logged.

 

[FlyingSparks5]

I would guess if the tracking had anything to do with it and I doubt it has the light would remain on all the time as the fault would be constant and also a light graze at 5 mph should not have affected the tracking anyway. The most likely cause is a wheel sensor or the wiring to it as either can cause an intermittent problem. To sort this you really need the fault code and I am surprised one has not come up as the light has therefore the car knows there is a problem. What did you use to scan it?

I suppose the sensor could be out of alignment with the hub very slightly but again a light graze causing this seems a very long shot to me.

 

[abyrne153]

A number of things can cause the ESP light to come on. Easiest one is a very underinflated tyre. The rolling circumference of the tyre changes in relation to the others and throws up a fault. Next is a wheel speed sensor as mentioned above. VCDS or similar diagnostic equipment will show the fault and you can monitor the wheel speed sensors by driving slowly and taking the readings from each wheel with the computer. This usually shows up the offending sensor. Finally wheel alignment - if the steering is not centred when driving straight ahead then the steering angle sensor sees a fault and throws up a code. Get it plugged in and see what codes you have.

 

[chris fry]

I would guess if the tracking had anything to do with it and I doubt it has the light would remain on all the time as the fault would be constant and also a light graze at 5 mph should not have affected the tracking anyway. The most likely cause is a wheel sensor or the wiring to it as either can cause an intermittent problem. To sort this you really need the fault code and I am surprised one has not come up as the light has therefore the car knows there is a problem. What did you use to scan it?

I suppose the sensor could be out of alignment with the hub very slightly but again a light graze causing this seems a very long shot to me.

Thanks for your response, and yes i would be surprised if the graze would cause it but in the absence of any other event it could only otherwise be coincidence. i read the code with a obdii app and dongle, so im sure a full reader would give better analysis.

 

[chris fry]

A number of things can cause the ESP light to come on. Easiest one is a very underinflated tyre. The rolling circumference of the tyre changes in relation to the others and throws up a fault. Next is a wheel speed sensor as mentioned above. VCDS or similar diagnostic equipment will show the fault and you can monitor the wheel speed sensors by driving slowly and taking the readings from each wheel with the computer. This usually shows up the offending sensor. Finally wheel alignment - if the steering is not centred when driving straight ahead then the steering angle sensor sees a fault and throws up a code. Get it plugged in and see what codes you have.

Thanks, i hadn't thought of the tyre pressure and it makes sense with the circumference, same way as tyre pressure monitors, its also quite possible i lost pressure breaking the seal on the tyre against the curb, ill try that first.

 

[chris fry]

checked tyre pressure, it was the same as the others. ESP came on again this morning after 20mins on the motorway, accompanied by a bouncing speedo needle, never seen that before. i slowed down and it stabilized, before i stopped i started the obdII app and it had a pending P0600 fault, stopped engine and fault disapeared. restarted car later for journey home, no ESP or needle issues. weird!

 

[FlyingSparks5]

Could have something to do with the vehicle speed sensor, bad connection, sensor on its way out, but there are other issues that could cause this and it could very well be linked to the ESP problem. P0600 is a generic code as denoted by the fact the code starts with a zero and not Audi specific, of the top of my head I think its a communication malfunction but still not enough to help to pin the problem down. You really need to get this vehicle scanned with VCDS or similar.