ecooney

Hi All,

I am having an issue with my car at present. It is firing the P0620 code intermittently for the past few days. Over the last year I have replaced the alternator and battery as these were the initial points of failure. The car has had 2 alternators before the mechanic realized that it might be something else causing the issue.

I have my own code reader and get the P0620 code only - no other codes. When the fault appears the battery indication light comes on the dashboard and the stereo switches off (I'm assuming to conserve power). If I use my code reader to clear the code the stereo will come back on and everything is fine.

The problem I have is that this code may not appear again for another 2 months but when it does I'm generally on a long run to the airport or a meeting etc and unless I pull in every 20 seconds to reset the code the car just dies completely.

I really need to figure out what else could be causing this error.
I've been told that the PCM / ECM could be the cause but wondered should there be something else I could look at before going down this route.

I've talked with 2 Mercedes specialists and they say that unless the code is being fired constantly to fault find then there isn't much they can do.

All help would be appeciated.

Thanks