I have an E85 06 3.0SI where the DSC keeps kicking in under normal acceleration. Im getting no codes on the DSC (or anything related across the other modules) either via ISTA or AUTEL OBD dongle. Most posts seem to suggest wheel sensors, ive replaced one that was erroring and they all seem to read fine when monitoring their behaviour whilst driving
To turn back the clock .....the issue started Christmas Day, driving cross country for xmas dinner, when i got the dreaded orange trifecta. I didnt have my laptop with me, managed to get to my destination, called out RAC over the xmas break who reset my codes (DSC module and rear wheel sensor)
Test drove the car and all was fine and the car got most of way back home, before starting to do the overactive DSC thing. I got home, plugged in ISTA and car was again throwing just Rear Left Wheel Sensor Plausibility.
I didnt have a wheel sensor so - had a look at sensor wiring - which seemed ok but reluctor ring was coated in what looked like plastic and some debris in the slots, but nothing crazy. I cleaned the ring thoroughly so it was shiny and refitted the old sensor. Cleared codes, and ta-da everythign was fine
...for about 50 miles. now im getting the same over active DSC ...but havent had any codes since. Ive been living with it as im not really using it much and it behaves more or less fine with the dsc partially off
Ive since....
- replaced the rear left sensor
- got a OBD dongle that has a live feed, and ive checked all the speed sensors and all seem to be reading normally (ie all wheel speed sensors seem to read roughly the same value - none drop to zero or read erratically)
- recalibrated the steering (steering sensor also seems to behave as expected on the live feed)
- yaw sensor appears to behave fine - ie not cutting out when im getting the dsc light and values seeeeem to represent what happening in the car
- Using the live sensor feed - ive been monitoring the overactivity (getting DSC to come on under normal driving) - as i mention above i see nothing obvious across the sensors. However under hard acceleration or if the DSC kicks in repeatedly (like in motorway driving) then it seems as if everything resets!!! The DSC light flashes repeatedly and all the sensors read "n/a", and the car basically goes into limp mode for a few seconds (though its tough to tell if its limp mode or just cutting out under DSC anyway). After a couple of seconds all the sensors read normally again and it goes back to normal over-active behaviour
- The brake pedal pressure sensor always seem to read 1 bar (not sure if this is normal ) - but overwise behaves normally under normal braking
- Even with DSC partially off - its still sensitive in specific circumstances - and I get the DSC coming on occasionally but only when accelerating with hard steering (not necessarily aggressively - ie turning into a 90 junction)
- On replacing the wheel sensor i was getting some rubbing for a couple of miles on uneven roads - suggesting maybe the reluctor ring has corrosion underneath but i couldnt spot any through the little hole
- Replace all the wheel sensors / new reluctor rings (im a little 'reluc'tant (sorry) to do this as they all seem to read fine)
- Second hand / refurbed abs module
- possibly Yaw sensor (though facelift ones are hard to get hold of)
TL;DR - DSC keeps kicking in under normal acceleration. Im getting no codes