2003 grand prix cooling fan inop

sden

2003 grand prix cooling fan inop

Unread post by sden » Fri Jun 11, 2010 8:24 pm

2003 Grand Prix SE. The cooling fans do not come on unless the air-conditioning is turned on. Tried replacing the coolant sensor but it made no difference. Fan relays seem to be good as well as fuses. Any ideas?

Meccboy

Re: 2003 grand prix cooling fan inop

Unread post by Meccboy » Sun Jun 13, 2010 4:31 pm

The cooling fans are controlled by the powertrain control Module (PCM). You would need a scanner to look at the live data to see if the computer is seeing the coolant temp high enough to turn on the fans. Low speed will not come on until about 226 degree.
If the PCM data shows the coolant temp is high enough, but does not show trying to energize the relay, then you may have a PCM problem.

sden

Re: 2003 grand prix cooling fan inop

Unread post by sden » Mon Jun 14, 2010 1:46 pm

Thanks meccboy. Turns out that the new coolant sensor was no good. Out of box failures sure add a lot of troubleshooting time. Anyway, its working great now.

Meccboy

Re: 2003 grand prix cooling fan inop

Unread post by Meccboy » Mon Jun 14, 2010 7:01 pm

Hey, cool. Glad to hear it.
Sometimes those new part failures are the hardest to find !

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