99 Sunfire 2.2L overheating

Tiny
JETSTREAM
  • MEMBER
  • 1999 PONTIAC SUNFIRE
I have a 99 Sunfire 2.2L no A/C, Auto and 105,000Km.

The cooling fan is not turning on at all. The fuse, the relay, the coolant temp sensor, and the fan itself have been checked and work perfectly. I have also checked the circuits for the coolant temp sensor and the fan and they to check out okay.

However when I unplug the coolant temp sensor (with the engine running) the cooling fan comes on right away. My guess is the PCM.
Anyone have any other ideas?
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Saturday, September 1st, 2007 AT 11:37 AM

2 Replies

Tiny
RASMATAZ
  • MEMBER
The PCM commands the cooling fan by grounding the relays. Its a lot cheaper just to hot wire the fan motor than to replace the PCM by using its power source and ground.

Good luck.
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Saturday, September 1st, 2007 AT 3:29 PM
Tiny
JETSTREAM
  • MEMBER
Thank you for your quick response!

I take it from your reply, that the PCM is the problem then. Thanks for the tip on hot wiring the fan but I have sourced a PCM from a wrecker for very cheap ($60.00 and tested).
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Saturday, September 1st, 2007 AT 5:48 PM

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