My 88 Euro 560SEC has been driving quite well but recently, when taking hard corners or driving a little enthusiastically, what appears to be a check engine light goes off and the pedal becomes very stiff. I was not aware that this system is drive by wire but I guess it must be, and is going into some sort of limp home mode.

For a while, this would happen and all I needed to do is turn the engine off and restart, but on the most recent occasion, the problem would not go away upon restart.

As this is not like anything that I've experienced so far. I'm wondering if anyone else as an ASR equipped W126 who may shed some light on how to diagnose the problem.

I posted to a W126 specific forum and was told that it may be a TPS and that parts are really expensive and these systems are a nightmare.

I can imagine it getting really expensive if I start throwing parts at it, so I was wondering if there is a diagnostic process that I can go through in order to trouble shoot the problem.

__________________
With best regards

Al