08 Impala SS

Dead Battery and service charging system message one day.
I charged the battery, and tested voltage at idle, only had 11volts.
I replaced the alternator and it worked fine for 3 days, Then the Service Charging System came on again. Voltage again is only showing 11 volts.
Then I learned about the stupid Battery Current Sensor, Mine was stamped with the old part number. I replaced it with the GM superceded part number and voltage again showed 14+ at idle. I thought I was good to go but now a mile away from home, the same Service Charging System came on and voltage is back down to 11volts.

What can cause this intermittent issue?

 

As far as I remember and could be wrong but there are 2 different sensors, a first and second design. The voltage was different on them, I don't think you can just use the later. Not sure if that is what you what you mean by superseded part number. What number did yours have and what did you replace it with?

 

5V: P/N 13505369

10V: P/N 10306471

my car had the 10v part number originally, but I tested the plug and it produced only 5v, so I installed the 5v part number. I was explained by someone else that if I left the sensor unplugged, the alternator would produce a static 14volts instead of variable by the ecu.
Even with the sensor unplugged, I was only producing 11 or less volts. effectively, no charging from the alternator at all.

 

Well I think you installed the incorrect part, there may be more to that voltage then just testing the plug. Hopefully someone in the know chimes in.

 

have the battery load tested and work from there.