I had a battery CEL light come on yesterday. I took the battery to have it
tested and it failed to hold a charge. Since it was only 16 months old it
was replaced by the store where I purchased it free. Anyway, I put the new
battery in the truck and the CEL is still on. Is there something in the GMC
that requires codes to be reset by computer to get the CEL to clear? If the
problem that caused the CEL in the first place was the bad battery, should
the warning light have gone out once the new battery was installed? Ideas.
Dave in WA State