I can't seem to narrow this down, but on my 92 AFTER the car gets to operating temp, the SES light and then shortly after, the ASR light comes on. The engine will then start misfiring and it's limited to no more than 3,000 RPM. I have had the ECM rebuilt twice but what I can't figure out is what relationship the check engine (SES) light has to the ASR light. 

Strangely, after the car cools down, all is well again. Any ideas are most welcome. I think a sensor, a plug wire, or a ground is the issue, but I just don't see how those things can light the ASR light at the same time as the SES light. The engine misfires should have nothing to do with the ASR!

Thanks.

Refreshing this message. It is possible that Adams' Apple will have an answer for you.

Guess I did miss this one!  An engine misfire can definitely cause the traction control(ASR) to go offline. The ASR controls the throttle input when needed, and if an engine related problem arises that would effect that control, the light will flash/come on, indicating that the system MIGHT not be able to function as designed. You need to determine the cause of the engine misfire first, correct that, and then the ASR system will function properly. If you can access the on board diagnostics, you should be able to retrieve engine related codes that would point you in the direction of the misfire cause(s).

Thanks Adam. You are the first person I asked this question (and I asked plenty) to have a definitive answer. No one seems to understand the mysterious C4 wiring.