[fl00rit]

I've got an '02 convertible (Imola Red/Black) with 86k. Recently it started automatically turning off the DSC shortly after I start driving. Sometimes it pulses the ABS for a few seconds and flashes the DSC before finally disabling it and calming down. When the DSC light goes on, the tire pressure light usually goes on as well (both amber).

I searched here and figured it was a wheel speed sensor or the steering sensor. I took it to a mechanic and he got the following codes:

A1 Rotation-rate sensor
A2 Rotation-rate signal

He couldn't get a specific wheel to trigger it on the lift, so he said to just keep driving it and see if we could get a more specific code. I don't want to replace all four wheel speed sensors, but I don't want to just "wait and see," either. I live in Massachusetts and have to drive this in the winter!

Tire pressures are all balanced at 31.

Anyone seen this type of thing before? Any ideas on what the problem could be?

Thanks.

 

[flow350]

Seems like you already answered the question. With those codes, you should be targeting a wheel speed sensor. Why not buy one and swap it from wheel to wheel until you find the bad part?

 

[fl00rit]

He showed me the codes from another car (don't know the year) with a definite wheel speed sensor problem. I don't remember the number, but it was specific, like "FR Wheel ...". So that made me wonder if it really is a wheel speed sensor vs. some other electrical problem that might be affecting the signal from all wheels. Especially since he couldn't cause a failure from specific wheels on the lift.

 

[Cazz]

Are you sure that is a wheel speed sensor code? It looks like a yaw rate sensor code to me.

 

[fl00rit]

Thanks for the tip on the yaw sensor. I picked up a used one for $100 and the lights have stayed off since. The instructions I found online didn't quite match my m3, so I'm including a picture of what I actually found. The sensor I replaced is by my thumb; it was to the left of the driver's seat, not in front of it.