Anyone have and experience diagnosing a 2E3C alternator code on a 2010 cooper s? Any help would be appreciated.

 

Symptoms?

Crank, no start?

 

cranks and starts fine. Alternator’s putting out 14.1 - 14.2 volts

 

2e3c is not an alternator fault code.

 

 

Your posted voltages do not reveal a charging issue, though you did not mention the test conditions.

If you clear 2E3C, does it return?

 

yes. It clears and doesn’t return until I start the car again. New battery installed and coded and alternator was replaced about 12000 miles ago with OE alternator.

 

Any voltage deviations under the three conditions shown in post #4.

 

How long after changing the alternator did the code start showing up?

https://bmwfault.codes/XMLDiagView?d...QANwA4ADAANAA=

Sounds to me like the alternator is the wrong amp size, and is putting too much voltage into the system.

 

Did the test as described and had 12.2v with key off and maintained 14.4 volts throughout the test with car running.

 

It's not causing 2E3C, but your battery voltage is clearly too low. You should charge the battery.

Also do the other two tests while monitoring the system voltage in an attempt to expose a charging issue.

 

purchased the bimmerlink app and used that to monitor the voltage and amperage and noticed the reading for amperage doing something crazy. It fluctuates between 30 to 50 amps which is normal and the reading jumps to 255 amp and stays there and then starts reading normal again after a minute or so and keeps doing that. Normal reading then 255 then normal reading then 255 and so on.

 

Replace the alternator and then go from there.