2003 Chevrolet Malibu coolinf fan

RAYJROB

MEMBER
2003 CHEVROLET MALIBU
3.1L
6 CYL
2WD
AUTOMATIC
85,000 MILES

My cooling fans don't come on even when my temp gage goes to red.I took the cover off the relay and engage it manually and they come on. The relay isn't getting the 12volts to the coil to engage it.

Tuesday, September 9th, 2014 AT 5:41 PM

5 Replies

JACOBANDNICKOLAS

MECHANIC
108,300 POSTS

The coolant temp sensor sends the signal to the PCM to engage the fans. Check the sensor first, check wiring between the sensor and the PCM, and check PCM if needed.

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Tuesday, September 9th, 2014 AT 5:54 PM

RAYJROB

MEMBER
8 POSTS

How do I check the pcm

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Tuesday, September 9th, 2014 AT 6:11 PM

RAYJROB

MEMBER
8 POSTS

If the gage works does that mean the sensor is working properly

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Tuesday, September 9th, 2014 AT 6:12 PM

JACOBANDNICKOLAS

MECHANIC
108,300 POSTS

I can't remember for sure on an 03 and can't get to my manuals, but some of these vehicles have a temp sending unit for the gauge and a coolant temp sensor for the fans and so the computer can determine proper fuel mixture based on temp.

From what I remember, the relays get power from the underhood junction box. Have you checked for any blown fuses there? Also, I believe there are three relays and they run in a series for your system. Have you found 3 and been able to check if all don't have power?

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Tuesday, September 9th, 2014 AT 6:24 PM

RAYJROB