Mechanics

ENGINE COOLING FANS

2000 Pontiac Grand Prix

Engine Mechanical problem
2000 Pontiac Grand Prix 6 cyl Front Wheel Drive Automatic 101100 miles

My Grand Prix was just in to have my auto start re-programmed (AstroStart). I noticed that after it was programmed that my engine cooling fans don't turn off. Now, my car did this about 2,000 miles ago but the Service Engine Soon light came on and it was a bad thermostat which was replaced. Currently, the car sits at the right engine temperature and runs perfect, except the 2 engine cooling fans located directly behind the radiator don't turn off but rather stay turning all the time. It's about 20 degrees where I currently live and I know that when I warm up the car the cooling fans should not be running for obveous reasons. I don't know if the programming of my AstroStart has anything to do with it or maybe the timing was coincidence. I know this is abnormal because my car has not done this before. Do you know what the problem could be?
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Austinhenre
February 9, 2009.




Hello –

To better assist you please let me know if your model is a GT, GTP or SE. Also I need to know the 4th and 8th digit of your VIN and your engine size in liter.

Please go to Auto Zone (AZ) or O’Reilly’s (OR) and for FREE they can pull the codes to the car. Most important: Once they check your codes, if they find something and you don’t get it fixed and need to get back with us, please make sure you tell us exactly what the code was, number and all. Example, if the code was E0568 O2 Sensor bad. Then make sure you give us all of that. While there for FREE also they can bring their tester out and check your battery and alternator.

Thank you very much for the donation

Please let us know if what the final fix was for your car so we can better assist others. Thanks!

Find a car repair manual for your car repair questions.

ImpalaSS
Feb 12, 2009.
It's a GT, 3.8L V6. The 4th digit of my VIN is W and the 8th digit is K.

I am not near an Auto Zone or O'Reilly unfortunately. And maybe I misunderstood you but the service engine soon light is not on at this time. I was curious if the codes you were referring too were the codes of the service engine soon diagnosis. So right now just the fans are running constantly with no service engine soon light on. Perhaps this will help you?

Tiny
Austinhenre
Feb 13, 2009.
Hello –

Thanks for the info…….

The light does not have to be on to have thrown a code. Some – the light comes on – a code is thrown and when the key is cycled the light is off but the code remains.

Below is some info for you………. The last item is the actual fans are always on troubleshooting.

Inside Electrical Center At Right Side Of Engine Compartment

3.1L & 3.8L " W" BODY (GRAND PRIX)
NOTE: Cooling fan circuit utilizes 3 cooling fan relays. Relays directly controlling fan motors are 4-pin type and are referred to as No. 1 and 2. Relay determining cooling fan motor low speed or high speed operation is referred to as 5-pin relay in this test. See WIRING DIAGRAMS.

Cooling Fan Always On (3.8L)
1. If diagnostic system check has been performed, go to next step. If diagnostic system check has not been performed, see DIAGNOSTIC SYSTEM CHECK.
2. Turn ignition on, engine off. If one or both cooling fans are on, go to next step. If one or both cooling fans are not on, problem is intermittent.
3. If both cooling fans are running continuously, go to step 5. If both cooling fans are not running continuously, go to next step.
4. Remove cool fan relay. If left cooling fan turned off, go to step 6. If left cooling fan did not turn off, go to step 7.
5. Repair short to voltage in right cooling fan supply voltage circuit. After repairs, go to step 8.
6. Repair short to voltage in right cooling fan low reference circuit. After repairs, go to step 8.
7. Repair short to voltage in left cooling fan supply voltage circuit. After repairs, go to next step.
8. Operate system to verify repair.

Thank you very much for the donation

Please let us know if what the final fix was for your car so we can better assist others. Thanks!

Find a car repair manual for your car repair questions.

ImpalaSS
Feb 13, 2009.
Hello –

Hey - Also, it looks like you may have some recalls on your vehicle. The dealer may fix these for free. Please contact the dealer service department, give them the VIN number of your car and have them check on these to see if they apply to you.


http://www.2carpros.com/forum/automotive_pictures/248015_Picture1_53.jpg



Thank you very much for the donation

Please let us know if what the final fix was for your car so we can better assist others. Thanks!

Find a car repair manual for your car repair questions.

ImpalaSS
Feb 13, 2009.
Hi,
Turns out I had the car brought in and it had a code of PO128 ECT below thermostat regulating temperature. The code was reset and my cooling fans operate as normal. Although they did not that my car only runs at 150 degrees down the highway, my car has always ran cool in the winter versus about just under 210 in the summer. I put a new thermostat in about a month ago and I know Grand Prix's like mine also run cool. I don't know why but I wonder if maybe that's why it takes my car so long to warm up, any thoughts? Anyways, it's fixed now and you know what the problem was.
Thanks,
ahenre
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Tiny
Austinhenre
Feb 20, 2009.
Hello –

Glad it is fixed.

Yes – the higher the thermostat the hotter the engine must get to open it. Some cars are pretty sensitive and will trip a light if the thermostat is a little slow…. Though within operating limits.

Again, glad it is fixed…. Thanks for letting us know.

Thank you very much for the donation

Please let us know if what the final fix was for your car so we can better assist others. Thanks!

Find a car repair manual for your car repair questions.

ImpalaSS
Feb 20, 2009.

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