ace573 Report post Posted August 25, 2021 Hey all! Yesterday my battery light came on. Drove for couple minutes, turned on lights as it got dark and light went off. Got home, checked with multimeter and alternator is charging(14.2V) and battery voltage is also good. Light is off. On normal car I would replace the alternator, which I am leaning towards here as well. But since PCM controls Alternator on the edge I am wondering if something else might be happening? Any thoughts? Share this post Link to post Share on other sites
akirby Report post Posted August 25, 2021 You can’t go by voltage on the battery. You need a digital tester to check CCAs. If it’s more than 3 years old I would just replace it and see if that fixes the problem. If not then you can rule that out and not worry about it for 3-4 more years. Share this post Link to post Share on other sites
EddieHudson Report post Posted August 25, 2021 4 hours ago, ace573 said: Hey all! Yesterday my battery light came on. Drove for couple minutes, turned on lights as it got dark and light went off. Got home, checked with multimeter and alternator is charging(14.2V) and battery voltage is also good. Light is off. On normal car I would replace the alternator, which I am leaning towards here as well. But since PCM controls Alternator on the edge I am wondering if something else might be happening? Any thoughts? The same thing happened to my 2010 SE last year. With the light off, everything was fine. With the light on, no charge from the alternator. Battery SOH = 100%, SOC = 98%. I changed the alternator (PITA) and haven't had a problem since. Share this post Link to post Share on other sites
handfiler Report post Posted August 25, 2021 4 hours ago, akirby said: If it’s more than 3 years old I would just replace it and see if that fixes the problem. If not then you can rule that out and not worry about it for 3-4 more years. I wouldn't buy a new battery until I actually confirmed that the battery is bad. Share this post Link to post Share on other sites
akirby Report post Posted August 25, 2021 55 minutes ago, handfiler said: I wouldn't buy a new battery until I actually confirmed that the battery is bad. If it’s more than 3 yrs old it’s either bad or about to be bad. Obviously it’s good to test it IF you have a digital tester that measures CCA and not the old style testers or voltmeters. Those are worthless. Share this post Link to post Share on other sites
ace573 Report post Posted September 13, 2021 Was the alternator. I checked voltage again the next day and it was not charging. Replaced it and all is good again. Replacing alternator was not that bad, but then again I was an auto tech. Share this post Link to post Share on other sites
