Hi everyone,

I usually try to help Chevrolet owners here as often as I can, but I am having issues with OBD code P305F. It means that the auto start/stop module or something to do with it is setting this code off, and I have done everything I can to repair this issue, according to GM's service bulletin to no avail. Sure, I can clear the code out with my Innova CarScan Pro 5610 easy, but it keeps coming back after about 5 to 10 miles. Both the main battery in the engine compartment and the auxiliary battery in the trunk check out as quite normal, as does the alternator. CCA on both batteries are still quite high as well..

All wires and cables are very clean and tight, in fact, immaculate. Nothing looks odd at all but the dash indicator keeps coming back on, although the start/stop function still operates normally as does my 2015 Chevy Malibu. I'm now guessing it's the dual battery control module has gone bad. $200 USD to replace. Any ideas appreciated, up to and including disabling the start/stop function, appreciated.

-Oilcanhenry.

 

Fixed it! Put it on a 2 amp trickle charger on the main battery for a few days. Cleared the code with the Innova scan tool. It hasn't come back for three weeks. The alternator is fine at 13.9-14.2 volts. Who knows why it worked. I just took a guess, and it works fine. Hoo-rah!