Overvoltage?
 

Hi all! I need help here!

Recently my red battery light in instrument cluster lit up several times, each time it lit up, it only stayed for several minutes and went away. I used DIS to check the fault code today, it showed 7 times of 'overvoltage' (14.6V on alternator output, 13.8v battery) and 1 time no communication with DME.

Any idea on this? What is the problem? Is the alternator dying or the battery dying? Thanks for help!

Doesn't DIS have a test plan to use?

However, I would think its a bad alternator/regulator causing the over voltage and not a bad battery.

Yes, i tested the alternator, but it worked well. Since the battery light was out when I was testing/checking it with DIS, so everything worked well. However, the fault memory was there.

Got it. From what I remember, the battery light is not really a light to indicate a bad battery but something is wrong with the charging system. So, probably your alternator/regulator is going bad.

When I had a bad battery, the battery idiot light never came on. However, I didn't check if I had over voltage problems and don't remember if I had any codes related to that issue.

Maybe try to use DIS when the issue happens again, if you have the opportunity.

You said it was only on occasion? Sounds like the regulator is going bad.

Over voltage is caused by a bad voltage regulator. It can fry your electronics.

Thanks for comment！ l think l must deal w/ it asap.