Just wondering if anyone can offer any insight to something that happened to my truck a couple days ago. I accidentally left my parking lights on and battery went way down. Enough it wouldn't start but had a little power. Let it sit for a couple hours and battery came back enough to barely start the truck. OK, now the truck started but would not idle at all. Anything over 1000rpm seemed to run ok, let off gas and die. Let it run enough to charge battery back up and let truck sit for 24 hrs and now it idles fine but runs just a little rough. Its got me baffled, '01 1500 5.9L 4x4 auto. Sorry for being long winded but had to explain somehow, any thoughts anyone? Thanks in advance for any advice.

 

How many miles on truck? Is it original battery?

 

Have your alternator tested. Places like Autozone do it for free. I bet it is on its last leg.

 

truck has @80,000mi. Has NAPA one yr old battery.

 

PCM just lost it's memory due to the weak battery. It had to relearn the IAC for your idle and will continue to adapt. It should smooth out to how it was before in a few days.

 

^+1-Rabbler nailed it, the exact same thing happened to me, same situation and everything... give it a few days

 

check the batt. mine did the samething when my batt. was junk. replaced it and itsbeen good sence.

 

same thing happend to me the computer just reset it just has to go to school haha start to learn

 

did it ever go away?
did the PCM "learn"?

 

+2 What he said.