I would clear all the codes and see which ones come back. The brake lamp switch is only about $30 and you can change it in 10 minutes. The Neutral Safety Switch is about $130 and that can be changed in less than an hour.

Last week, I was getting an erratic idle, pointing to a fault in the EA/CC/ISC. The car had just been driven in heavy rain. I cleared the code and the problem has not returned (so far). If it does, my first action will be to replace the NSS.

When I was at the dealer last week, I asked the tech why there was a 500E in the repair lot. He had not looked at it yet, but he said it was an ASR light and suspected that it might have been the NSS getting wet with all the rain. It's a cheap place to start.

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1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles