I want to pass on more info that might help other C6 guys regarding battery glitches.

I have an 08 with 65k miles on it. For the last few months I've been bothered by occasional check engine light due to EVAP and TPMS faults. Yesterday, I purchased new tires and TPMS modules. When the installers tried use the fob it failed to work when they tried to initialize the TPMS. Further, the fob wouldn't lock or honk the horn. When I tried to start the car, it needed a jump.

This was the second time the battery died, so I knew it was time to get a new one.

As soon as I installed the new battery, the check engine light cleared. Now I have to wonder if I needed the TPMS modules replaced or if was due to the old battery?

Anyway, the car is glitchy as reported elsewhere when the battery goes down. And even though the car needed a jump the day before, I believe the battery might've been weak for sometime. Hence, the engine light being cleared.

The voltmeter was showing in the 13.8 range, so it's not an indicator.

The TPMS and EVAP fault (even though the gas cap and EVAP module had been replaced) has been an annoyance for months. Hopefully the new battery will solve these problems. And perhaps this experience will help other C6 owners that experience "glitches".

 

The voltage guage was an indicator. You need over 14V to charge the battery. 13.8 V shows something is wrong. Mine puts out 14.6 volts all the time (upgraded alternator).

 

why did you upgrade your alternator? My new battery still shows 14v and under.

 

13.8 V is a perfectly acceptable amount of voltage to have the battery charge properly.

 

yep, I agree. But it still doesn't give us a clue about a "glitchy" battery. I suppose I could do a load test whenever I got a recurring engine fault or something. It's just an annoyance.

I just wanted to pass on my experience in case someone has a similar problem, particularity some long term but intermittent annoyance.