PCM weirdness

[rick121]

I'm having this strange problem with my 98 3.8liter camaro. I recently completed a COMPLETE drive-train swap and it was mostly done well except a few loose bolts here and there but the weird issue i'm having is that every 200 miles or so my PCM resets itself. sometimes its while driving and the gauges freak out for a second and the tripodmeter resets. during that time the drive gets rough as the pcm starts to re-learn the settings and everything. then its fine for the next 200 miles or so. always does this between fill-ups at the local exxon or wherever i am.

I've checked the grounds personally and paid a shop to do the same and figure out the problem. they suggested a new PCM because it used to have the problem every ten minutes. now it occurs much less frequently (since the PCM swap) but still does. what's with that?

[ScottS4050]

Re: PCM weirdness

I know you said you already checked them, but check the grounds again. Also, check the connections at the fuse panel and at the pcm itself. You say the pcm has been replaced? Then it is probably not the pcm.
My guess is a loose connection either at the ground, or at the hot. Maybe a short in the harness somewhere. Had any issues with pack rats?

[ScottS4050]

Re: PCM weirdness

Just another thought, have you checked to make sure your battery terminals are really tight and free of corrosion?

[Bird_Of_Prey]

Re: PCM weirdness

x2 on battery terminals, not just clean but make sure the battery doesn't have a loose terminal as well. Trip mileage isn't stored in the PCM, it's in the BCM.

[rick121]

Re: PCM weirdness

well there you go maybe it is the BCM then... but every time the trip goes the car seems to forget the settings and yada yada yada. sorry it took so long to answer. I will go over my grounds again but i don't think the issue is there... I checked and torqued them, a shop checked them all and I've added in extra grounds to be certain. The PCM could still be bad. I just got a bad one and had it warrantied. I checked the terminals again and they were tight (brand new battery, clean no corrosion yet)