# 2000 Malibu cooling fan won'T turn on



## simlarock (Aug 2, 2008)

Hi.

I've Been having problem with my 3.1L, overheating. The cooling fan isn't coming on but if I disconnect the sensor it will the temp gauge will come down and the car won't overheat, howerver the check engine light will come on and the transmission will engage really hard. My mechanic replaced the coolant, rad cap, thermostat, temp sensor and fan still not coming on engine still overheating?!

Your help would be greatly appreciated.

Thanks


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## Midnight Tech (Dec 31, 2001)

Check the cooling fan relay - sounds like it's not working.


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## jimmy917 (Aug 7, 2008)

If the fan comes on when you disconnect the sensor, then you know the relay works. You have a command problem. To diagnose this correctly, you need to have a scan tool plugged in, and see when the temp climbs high enough, if the PCM requests the fan to come on. If the request is there, but command never happens, then you have a bad PCM. Another thing to watch is for a blown head gasket. Coolant sensors cannot read correctly if there is air in the system. A blown head hasket will pump air into the cooling system, causing erratic gauge readings, and eventually overheat.


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