I didn't think the 600SEL came out until 1992, you cannot read asr codes with the impulse counter until 1993-94. you must do pin tests, voltage / resistance etc.. codes with a scanner / impulse counter are only for diagnostic module, engine, abs and throttle actuator. The problem is probably the throttle sensor of the actuator but testing without known good part substitute is time consuming. We would charge 4hrs to diagnose the asr system. Be very careful with charging system problems and address them fist. Check the connection of the smaller wire at the battery positive cable end at the battery, I have seen other shops loosen this when changing a battery (it doesn’t need to be loosened) and then forget to tighten it. Good luck with the repairs, make sure to post what your ultimate fix is.

Jason Athanas
Autobahn Performance Inc
Ft.Lauderdale Florida
Jason@autobahnperf.com