tnank you very much for this information. This will come in extremely good use with my current problem.
I have a 1989 300E that has the "Check Engine" light coming on while the engine is turned off. This all began soon after I had my altenator replaced. I have done the diagnostic on the battery, starter, and recharging system and all checks out good. I have check and removed the fuses and the darn light still comes on when I turn my engine off.
Thanks again and wish me luck.