Question about 2002 Pontiac Montana

1 Answer

Cooling fan runs continuously, even after replacing both relays coolant sensor.

When ignition is turned off fans stop, when relays are removed fans turn off. Could problem PCM fan drivers?

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  • Pontiac Master
  • 5,495 Answers

Could be that you have 2 Thermal sensors as some cars have one for the dash gauge or light and the other is for the PCM.

Remember that when you turn on the A/C it can trigger the cooling fans to run continuously. If the A/C is left on while you are doing all of this, it can be a simple reason for the problem.

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Posted on Jan 03, 2013

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Posted on Jan 02, 2017

emissionwiz
  • 75797 Answers

SOURCE: cooling fan not working

The fans only run when the engine reaches approxminatly 235 degrees F. on the guage that is near the end of scale just before guage show "HOT" I don't think you have a problem, allot of folks out there don't know about this.

Posted on Aug 22, 2008

  • 1596 Answers

SOURCE: 95 grand am radiator fan only runs with AC on

Cooling Fan Temp Sensor is the First thing You Check (with what you have described) Cooling Fan Should ALways come On When The A/C is turned On as A/C Adds A Load to Engine, If Temp Sensor is Faulty it Will Not Give GROUND Signal to ECM >For COOLING FAN >RELAY to Give ground and turn ON The Fan.
There ARE 2 temp Sensors that Serve Different Purposes 1 is for Dash READING GAGE & Or TEMP LIGHT the Other is For ECM or Fan Relay (SAME Thing) you Said>""can disconnect the sensor and fan continues to run" < This Leads me to think you Changed the Wrong One. Not Questioning your Skills Just Here to Help.
TEMP SENSOR FOR 3.1L V6 is Located upper RH rear of engine compartment, near exhaust system. Temp SENSOR for 2.3L Engine is Located in LH rear of engine compartment.
I Hope this Helps Lead you to a NON-OVERHEATING Pontiac.
Good Luck and Have A Great Evening. rejakwilson

Posted on Feb 04, 2009

  • 37 Answers

SOURCE: Cooling fans not coming on. Fuses are ok, replaced

The temp sensor is located next to thermostat housing.

Posted on Apr 11, 2009

  • 2 Answers

SOURCE: cooling fan wont turn on on my 2000 grand am

are you having a temperature problem? i heard that the cooling fans only come on at high temperatures, around 230F.

Posted on Jun 16, 2009

MNfisherman
  • 11896 Answers

SOURCE: Cooling fans not turning on

It may be the relay or a short in the wiring

Posted on Jul 07, 2009

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1 Answer

Cooling fan runs continuously, even after shutting the ignition off


sounds like it could be a relay.

With everything plugged in and the fans running with the key off remove the cooling fan 1 fuse. Do they stop?

If they do not stop remove the cooling fan 2 fuse. Do they stop?

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Cooling fan will not shut off continued even after ignition key is off and removed, and small black box in front of battery keeps making a clicking noice


That would be the relay box, remove the lid and remove the relay that controls the cooling fan circuit. and that would be the one making the clicking noise. It will probably be very hot, If you have pulled the right one the cooling fan will turn off. Replace it with a new one. Should be fine now, however in the event that the problem does not go away then replace the engine coolant temperature sensor. Good Luck From Ernie @ RedDeer, Alberta, Canada.

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Engine cooling fan run all the time when car is running. had t stat replaced recently. what controls the fan relay?. unplug coolant sensor and fan stays running. need a wiring diag.


Hi, the relay is turned on by the PCM based on data from the coolant temperature sensor. Disconnecting the sensor sends the computer into safe mode so it keeps the fan on. Check the sensor wire continuity to the PCM. If good, try replacing the sensor. Please let me know if you have more questions.
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Dec 31, 2010 | 2002 Mazda Protege

1 Answer

1996 Buick Riviera Cooling fan won't shut off. we


COOLING FAN IS CONTROLLED BY COOLANT TEMPERATURE SENSOR (CTS). REMOVE THE CONNECTOR FROM IT AND IT SHOULD STOP THE FAN.
OR JUST REMOVE BATTERYGROUND CABLE.
ITEMS TO CHECK OUT :

CTS,RELAY,CIRCUIT FOR SHORTS.
NOT LIKELY BUT IS A POSSIBILITY, THR ECU.

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1 Answer

Fan continues to run after car is turned off


The relay that controls the fan may have been stucked close. Pull out that relay, the fan should stop. Then examine the relay. Put 12volt to it, it should click, then click again when power is removed. If relays is okay final check is the temperature sensor associated with the cooling fan. Make sure it is not shorted. The resistance should varry with temperature. Use an ohmmeter, and dip it in hot water. Resistence should get lower as you dip in hot water. vice versa. Do the relay check first before doing all these CTS(coolant temperature sensor) check.

Jun 30, 2009 | 2005 Mini Cooper

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Engine cooling fan will not turn off


It is controlled by the Coolant Temperature Sensor. it is located on the engine by the thermostat housing. It is brass colored with a small plug going to the fans.
Did you recently change your battery or otherwise remove the battery ? Sometimes it has happened that the battery is removed and the fan will turn on and the check engine light.You can try and remove the negative cable wait a minute , then reconnect it back,.

Feb 12, 2009 | 1991 Chevrolet Beretta

2 Answers

95 grand am radiator fan only runs with AC on


Cooling Fan Temp Sensor is the First thing You Check (with what you have described) Cooling Fan Should ALways come On When The A/C is turned On as A/C Adds A Load to Engine, If Temp Sensor is Faulty it Will Not Give GROUND Signal to ECM >For COOLING FAN >RELAY to Give ground and turn ON The Fan.
There ARE 2 temp Sensors that Serve Different Purposes 1 is for Dash READING GAGE & Or TEMP LIGHT the Other is For ECM or Fan Relay (SAME Thing) you Said>""can disconnect the sensor and fan continues to run" < This Leads me to think you Changed the Wrong One. Not Questioning your Skills Just Here to Help.
TEMP SENSOR FOR 3.1L V6 is Located upper RH rear of engine compartment, near exhaust system. Temp SENSOR for 2.3L Engine is Located in LH rear of engine compartment.
I Hope this Helps Lead you to a NON-OVERHEATING Pontiac.
Good Luck and Have A Great Evening. rejakwilson

Feb 04, 2009 | 1995 Pontiac Grand Am

3 Answers

Van chevrolet venture 2000


Fifteen minutes! you have bigger problems than only the fans the fans are controlled by a thermo switch that is heated by the coolant, If you have no coolant the sensor cannot activate But fifteen minutes seems like you may have a headgasket problem and steam cannot heat the coolant sensor.OperationNotesThe electric cooling fan operates when the engine cooling temperature exceeds a certain value. The cooling fan on this engine is controlled by the Powertrain Control Module (PCM) . The PCM turns the cooling fan ON by grounding the coil of the cooling fan relays when certain conditions are met. When the A/C is requested, the cooling fan will also be turned ON.

Power for the cooling fan motors are supplied through Maxifuses(R). The cooling fan relays are energized when current flows from the fuses in the Underhood Accessory Wiring Junction Block, and through the relay coils to ground through the PCM. The Coolant Fan 1 Relay Control Circuit is grounded for low speed fans operation. During low speed fans operation, both fans run at a slow speed. The Coolant Fan 1 Relay Control Circuit is grounded for high speed operation. During high speed fans operation, both fans run at high speed.

IMPORTANT: When certain Diagnostic Trouble Codes (DTCs) are present, the PCM may command the cooling fans to run all the time. Perform the A Powertrain On Board Diagnostic (OBD) System Check prior to diagnosing the engine cooling fans.

For more information regarding the Charging System, refer to Charging System Description , and Charging System Circuit Description in Starting and Charging.

If a problem that involves the low speed cooling fan relay control circuit exists, DTC P0480 Cooling Fan Relay 1 Control Circuit should set. If the problem affects the high speed cooling fan relay control circuit, DTC P0481 Cooling Fan Relay 2 Control Circuit should set. A problem with the ECT sensor should set DTC P0117 Engine Coolant Temperature (ECT) Sensor Circuit Low Voltage, DTC P0118 Engine Coolant Temperature (ECT) Sensor Circuit High Voltage, DTC P1114 Engine Coolant Temperature (ECT) Sensor Circuit Intermittent Low Voltage, DTC P1115 Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage. Any of these DTCs will affect cooling fan operation and should be diagnosed before using the Electric Cooling Fan Diagnosis.

For more information regarding the Cooling System refer to Engine Cooling Fan Description - Electric, and Cooling System Description in Cooling System.


Here is the electrical schematic and how it all is suppose to work,
If you need any further help please contact me Thank you,Randy If you find this information helpful please give me a good rating

www.aceautomotive1.com

Aug 16, 2008 | 2000 Chevrolet Venture

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