sschw03

I have a 2000 Pontiac Grand Prix GT with the 3.8L engine. My SES light has been on for awhile and the scanner is showing P0480 code for a cooling fan 1 control circuit malfunction. Does anyone have a solution to this code problem? Anything would be great.

eippermx

Here's my suggestion/idea if I were troubleshooting this problem:

The code is saying that the computer is not seeing the proper voltage from the output circuit from the Fan relay.

I think a quick check of the fuse for FAN 1 (under the hood, passenger side fender) would be the first thing to do. If the fuse is good, look at the nearby fan 1 relay.
Since you have a scanner - swap the fan 1 & 2 relays. Clear the code out of the PCM, warm up the car, and see if you are still getting a cooling fan 1 control circuit malfunction code.

If you are still getting the code, inspect the harness from the fans to the PCM and over to the fuse blocklook. Also inspect from the ECT sensor to the main harness. The ECT sensor and its wiring is close to the exhaust cross over tube.

If there is nothing found, then I'd look at swapping the engine cooling temp sensor since it is the device that the PCM uses to make a decision to turn on FAN 1 (cooling fan located underneath the upper radiator hose).

Hope this helps...

__________________
mark


'04 GP GT1
'98 GTP
'98 GTP 4dr - Project car (newly acquired)
'99 GP "Flaming Tomato" GT

sschw03

Thanks for the reply. I did make sure the fuse was still good and did switch the relays, but the same code came up. Thanks for other options to try. Will try them and hopefully one of them solves the issue. The car runs good and never gets even close to overheating even with a/c on, but the light is so damn annoying.