View Full Version : PCM wiring schematic

06-30-12, 12:24 AM
I have a code P0480(low speed fan relay circuit fault) that's coming up on my car and I have diagnosed it back to a bad wire from the PCM that goes to the Low speed fan relay.

Anyone have the wiring diagram for the PCM wires out. I want to see if there is contiunity from the PCM harness wire to the Low speed fan relay wire. I'm guessing it's either a broken wire or an issue with the PCM. Hopefully I will find a damaged wire.

My wife organized my manuals and I am missing the one factory manual of three that has the info that I need!

06-30-12, 12:55 AM
lscts, what is your email address?

06-30-12, 06:35 PM
i can't send the engine electrical

06-30-12, 07:10 PM
See attached.

07-01-12, 12:35 PM
Thanks Guys, It looks like I should be able to figure it out with these!


07-02-12, 10:49 PM
Thought I would post an update on how I fixed my code P0480. My problem related to the wiring harness at the PCM. The green wire in the harness had come loose and actually was coming out from the harness a bit. I was able to use a small pointer and make it click back into the harness and away went the light and code. I also used a little silicone adhesive and put a small bead on it and let it dry to try and stop it from happening again.

At first it was an intermittant problem where the light would come on and off, so I guess it was working it's way out further over time.

10-23-12, 10:56 PM
hey man it seems like i am having a similar type problem as urs but on my 95 cadillac deville,ive checked everything and finally 2nite narrowing it down to the pcm hopefully,basically neither of my fans work they both have ground and power and i can send power to both w my power probe all the way from the bottom of the fan relays.so there seems to be no bas fuses,relays or broken wires from atleast there,the wire schematic i got 2day shows all the fans wire run to the pcm so i figured id ck it out 2morro,does that seem to sound about rite?thanks