Alright, I've got a '96 Z28 A4 with the TCS system. I had an issue with the throttle cable and needed a replacement, but GM no longer makes the cable for traction control cars... To get it up and running I changed the cable out for one out of a car without TCS. I'm wondering what the PCM is doing when it goes into low traction mode since the module is no longer controling the throttle position. I still have a reduction in power when it senses wheel slip, which I really didn't expect. I'm assuming that I'm pulling a lot of timing when the PCM goes into that "mode," but what else is it altering?

 

It's applying the brakes as well.

 

Hmm, I didn't think it touched the brakes when the TCS system came on. I just thought it used the same sensors as the ABS system...

 

That is the reason that the TCS cars have 4 channel ABS, so it can independently modulate the brakes to each rear wheel when it senses low traction.
It does 3 things (maybe more but I only know 3);
1. Kicks back the throttle
2. applies braking to the rear wheels
3. retards the timing.

 

To be honest, I'm a little reluctant to put the correct throttle back on it. It's much less obtrusive than having the throttle kick back at you... I want my cruise control though, so I guess I'll just have to deal with it.