Hi,
both fans on my V6 Malibu 1997 do not work. When the engine is running, I see the temperature going up and above the middle point of the gauge, indicating thyat the temperature sensor is ok. Since all the relays are checked fine, I thought that there may be a wiring problem between the relay box under the hood and the computer. I removed the PCM, found connector pins that go to these relays and shorted them to ground (one at a time). Both fans come on just fine.Made an assumption that transistors in PCM turning these relays are fried. Got a new PCM, made it to relearn the passcode, started the engine and got the same result - gauge shows rising temperature, but fans do not come on...I am perplexed!Does this engine have two temperature sensors - one connected to the gauge and another one to the PCM? Or is it possible that somehow signal from the sensors is reaching the gauge, but not the pcm?Will greatly appreciate your help!
Thanks,Vlad
I don't have the solution but I have the same problem. You are not alone. I have done everything you have done and have run out of options as far as fixing it with OEM parts. I am going to over ride the system with a hot wire and toggle switch and tie into the led wire on the #1 fan so when temp starts to rise past 180 degrees I can turn the fans on. Freeway driving is ok for me, no fan needed, just when I get off the freeway and around town engine gets hot. My toggle switch has a L.E.D. light in it to indicate the switch is on.
There is a coolant temperature sensor for the computer. And then there is a coolant temperature sending unit for the gauge. The coolant temperature sensor could be bad, telling the computer that the engine isn't as hot as it really is.
What did it used to do? Usually one fan will come on at start, sometimes it shuts off when the computer tells it to. Then the thermostats in the bottom hose will run the fans, when that water gets hot enough, they come on, if your engine does not get hot, they won't turn on. Did they come on before and stay on or what? I would check the thermostat, I have had a bunch of people complain about their fans lately. Hope this helps.
1,389 views
Usually answered in minutes!
I suspected something along this line. Thanks!!!
I see one sensor near the thermostate. Does it go to PCM or to the guage? Where is the second sensor located?
THANKS!!!
×