If you buy a remanufactured PCM you provide them the information they need to program it, basically your VIN and mileage.

It should be plug and play.

Before condemning the PCM, as I said earlier, look at the live data. You can watch the truck stall and see why. If you lose communication then the PCM is probably at fault but a short to the CMP or CKP can also cause problems.

 

Had hooked up for yesterday at dealership scanner showed everything operating normally. I changed spark plugs and all 8 coils due to corrosion in springs but no signs of a bad sensor just no comm. But then it comes right back

 

Brought my pcm inside last Night to see if keeping it warm and installing it while it was warm would work and it ran perfect this morNing no stalling at all. So I guess I'll b doing that until I can get a new one. Looks like a faulty reman pcm is the problem
thanks for everyones help

 

Great idea for narrowing it down.

What made you replace it the first time, same problem?

 

Okay, one thing to check before replacing PCM. The connections at the PCM itself. Just had this issue with my truck, driving me nuts for almost two months. Found by accident. Let my truck run and wiggled the plugs on the PCM and it would stall out. I removed the PCM thinking bad solder connections internally but even though the pins looked good, they were dirty. I used a brass brush and cleaned them up. I was a little reluctant in cleaning them with something metal but I took the chance anyway and it worked out. Loosing communication just like yours and then after awhile it would be fine. I also wired tied the plugs to keep them tite to the PCM. Problem gone..... Easy to check, doesn't cost anything and weather is definitely a cause. After recently moving here to Florida, it's very damp in the morning and condensation is everywhere so, I attribute this problem to that as well. You took the PCM inside but you had to unplug it and plug it back in making the connections a little better, probably why it didn't stall. I used autotap and checked all my sensors on a live graph, they were fine when I was having this problem. Tis what led me to start checking connections.

 

Connections are good can't make it stall if I wanted to by wiggling I even uncliped then slightly without taking off and truck still ran no stalling. I replaced it the first time because it was fried. I guess the gel covering the circuit was falling aPart exposing it to the weather. They also replaced the clips incase of corrosion but after that it ran fine for two years now it just doesn't like the cold

 

Wondering if I have had the same problem for years on my truck. It runs great and has no codes, but when it gets cold outside my idle will fluctuate when I put in the clutch. It bounces between 400-1000 RPM a few times until it finally settles down. Sometimes it will drop so low the truck stalls, or the lights dim because it is too low to keep the charging system going. I haven't replaced the PCM but have had this issue for years (over 6 now) and have replaced and cleaned sensors and the TB, IAC, etc. When you said yours was fried, did it truly leave you stranded? My cruise control also doesn't work and I get a P1595 and have replaced servo, checked vac lines, replaced switches, etc. I think it is a short in the PCM and may be related. Curious to know what happened with the first PCM you had..

 

gnelson49

Sounds like the problem I had it turned out to be the IAC was funky every extreme weather change like winter my idle would go weird for a few weeks. Get a higher quality IAC the cheap ones suck and have this idle problem.

It was a cheap 1 year old IAC that caused my idle problems

Cheap is not always the best choice

 

When mine was fried the truck wouldn't even start to me its sounds like your negative wires on ur batt could b going that or a ground. Check for those if not try ur throttle position sensor

 

If u have no codes definitly check ur grounds and batt. Also check the connections to ur pcm take the neg off ur batt nd unhook the three plugs on ur pcm nd look for corrosion and dirt. Can clean with electrical parts spray from any auto shop if none of those help get back to us