Guys maybe you can help.

My traction control system has stopped working on my 98 A4. When the tires spin is says traction system active on the dash but it does nothing to put the car back in control. There is no difference in the amunt of wheel spoin with the traction on or off. I am not getting any service traction system light. When i pulled the codes i have the c1241 which the car has had for the past 4 yrs and never impaired its ability to allow the traction system to properly function. The Abs works great but the traction system failing like this has me scared.

Any ideas what i should do to properly diagnose this.

 

You need to make sure you there actually is a problem. The easiest way to do that with a stock C5 is to switch the front and rear wheels. As soon as you start driving the car after the switch you should feel the PCM reducing torque when the EBTCM requests a torque reduction and the EBTCM applying the rear brakes. You should have problems driving the car with the traction control turned on. If you can get to a hill make sure TC is on then with the engine running stop facing down hill, put the car in nuetral and then take your foot off the brake. As the car coasts down hill the EBTCM will apply the rear brakes and the car will practically come to a stop if it doesn't come to a stop.

If no hill then coasting down from some speed will suffice. Just get up to speed without TC turned on, pop the car into nuetral and turn PC on and see if the rear brakes are applied.

A way to check for torque reduction is to leave the front and rear tires in their proper position but just find a driveway with a good bump between the driveway surface and the road surface. At just a couple of miles per hour hit the bump at an angle to the rear wheels do not hit the bump at the same time. If you have your foot on the throttle while doing this the car should feel like it practically stalls.

Bill

 

Are you using the internal DTC monitoring system to check your DTCs or a aftermarket scanner??



BC

 

I am using the internal DTC system for diagnosis.

I have not tried swapping the tires and the other tests mentioned, but i am certain the traction is not working since I can spin the tires like crazy taking off on a wet road without the car automatically backing off on the throttle upon initial wheel spin. The car is not stock. I can't pinpoint the exact day the TCS stopped working but I did replace the PCM due to a PO601 code several weeks ago. When i get a chance i will try the wheel swap test and report back the results.

 

I am using the internal DTC system for diagnosis.

I have not tried swapping the tires and the other tests mentioned, but i am certain the traction is not working since I can spin the tires like crazy taking off on a wet road without the car automatically backing off on the throttle upon initial wheel spin. The car is not stock. I can't pinpoint the exact day the TCS stopped working but I did replace the PCM due to a PO601 code several weeks ago. When i get a chance i will try the wheel swap test and report back the results.

 

When you swapped out the PCM, did you do this yourself or did the dealer do it? I ask, because RPO codes need to be programmed in for the car's installed options.

 

Did it myself. I ordered the computer and plugged it in and i did the PCM BCM relearn where you turn on the ignition for 10 minuts and off for 30 secs 3 consecutive times.

What re these RPO codes they told me i don't have to worry about this on the computer replacement thread i had going on when the computer fried. The PCM was flashed before installing it on the car based on my vin#

 

The RPO codes tell the BCM which options the car has. Seems to me they'd need to be set too but I'm not sure there is one for the traction control.

Peter