I posted about my problem before, my van won't start until after the dreaded clicking of the relays stops. I have read on here that it is the PCM 9 times out of 10. I can get one on Ebay pretty cheap right now, but how will I know if it will work in my van? The only info the seller has on the PCM is the truck that it came out of VIN number. Can I tell if it will be compatible with my truck by the VIN? I don't want to put a PCM that had the 5.2L engine in my van (3.9L) Also what would happen if I did? What my truck blow up? or burn up every sensor in it? Or would it just not start. My truck hasn't been having to hard a time starting lately because it is getting warmer out. When it is really cold is when I have the problems with the clicking relays. Any help is appreciated.
Craig
alloro
04-04-2008, 11:19 PM
No the VIN isn't enough, there is a number on the computer. This number has to match your's exactly or your engine will run poorly, if at all.
Craigabooey
04-15-2008, 05:00 PM
Alloro, There are groups of numbers on the computer casing. One group matches, the others do not. Can I try it? Will I damage something if it doesn't work? I don't want to make the problem bigger.
alloro
04-16-2008, 09:18 AM
Post the numbers that you have and we should be able to tell you if those are the correct numbers or not for a 94 3.9 van.
Chump
04-18-2008, 12:10 AM
The number on your computer should begin with 5602 or 5604 with 4 more numbers after it.
car54
05-23-2008, 08:36 PM
if you still have this problem, it's a weak capacitor in the pcm and fairly easy to fix, 470 microfarad, 25 volts the large one, the small one is the ignition module, solder a new one on and you're done.
