2004 E60 545i - Electrical Surges
 

I had a 12volt cell phone charger "burn up" whilst plugged into the back of the center console arm rest.

Immediately after, I got multiple system failure notifications, which align with symptoms of a "bad alternator".

The rear heated seat buttons will not stay on anymore when you push the button. The light stays on for 1/2 a second & then turns off, even when you hold the button down for a few seconds.

I replaced the fuze that was blown for the rear 12volt receptacle & have checked for other blown fuzes & cannot find any.

I replaced the alternator & replaced the BMW relay #6136-6901469 also.

I still get intermittent power surges & "dynamic drive malfunction / transmission error / etc." errors at random. Some days everything is great & no issues. Other days, the car idles up & down a little bit, which seem like "power surges".

I had ZERO of these issues before the cell phone 12volt charger burnt out.

Any ideas of the best route to troubleshooting this (besides going to the stealership) would be greatly appreciated.

Thanks,
boardtek

I had a similar problem
The cause was a bad voltage regulator in a Valeo Alternator
I replace the voltage regulator with an aftermarket model with a larger hit sink
I just completed a 3,000 mile road trip with no control module faults

If you decide to replace the alternator, get a Bosch unit