Cooling fan problems

if engine at long stand still,the engine temperature will rise about 190 degrees the cooling fan suppose to automaticaly turn on when coolant temperature sensor get hot it cause its resistance decrease causing pcm to send power to coolant fan relays and cooling fans, when you turn on AC the cooling fans suppose to turn on to cool down AC CONDENSOR, IF NOT AC WONT WORK COOLING FAN COOLS DOWN REFRIGERANT SO IT CAN RECYCLE THROUGH THE SYSTEM AGAIN.your cooling is suppose to turn on when engine at a sit still if vechicle not moving as coolant temperature rises at a set point the cooling fans will turn on cool down engine.cooling fans dont turn on when you first cold stsrt vechicle unless you have AC SWITCH ON.if cooling fans dont turn on when vechicle at a long stand still or moving along slow traffic.if coolant temperature sensor been replaced and fuses and relays okay have dealership check see if pcm driver circuit working faulty pcm will cause cooling fans not to turn on.

This is controlled by a cooling fan sensor/temperature sensor, as well as fuses, and a relay. These will have to be checked.

Make sure your coolant level is full, the coolant temperature switch won't work if the level is too low. If coolant is low, you need to find out where it went to by pressure testing the cooling system.

If it's not low and the fuses are good, the relay is working:

The fan should be tested, bypassing any sensors to make sure it is functioning properly.

The sensors can be tested to be sure they are working properly at the correct temperature with a voltmeter/ohm meter.

Reverse troubleshooting the wiring and ignition is the next step if you haven't found the problem.

Good luck !

CHECK FOR LOW COOLANT LEVEL AND REPLACE THERMOSTAT AND THE RADIATOR PRESSURE CAP.IF CAR OVERHEATING AND COOLING FAN NOT WORKING.CHECK COOLANT FAN FUSE AND RELAY.IF BOTH OKAY,HOT WIRE COOLANT FAN,IF FAN WORKS, PROBLEM COULD BE FAULTY COOLANT TEMPERATURE SENSOR,OR FAULTY PCM, IF COOLING FAN DONT WORK WHEN YOU HOT WIRE FAN.THE COOLING FAN ASSEMBLY NEED REPLACING.

REPLACE THERMOSTAT BUT IT SOUND LIKE FAULTY COOLANT TEMPERATURE SENSOR.BUT CHECK COOLING FAN FUSE AND RELAY.IF ALL IS GOOD HOT WIRE COOLING FAN IF COOLING FAN WORKS.PROBLEM COULD BE FAULTY COOLANT TEMPERATURE SENSOR. DAMAGE FAN WIRING OR FAULTY PCM.IF COOLING FAN DONT RUN WHEN HOT WIRED.REPLACE FAN AND MOTOR.

SCAN CAR FOR A FAULTY COOLANT TEMPERATURE SENSOR.IF SENSOR GOOD CHECK COOLING FAN FUSE AND RELAY.IT BOTH OKAY.HOT WIRE COOLANT FAN USING JUMPER WIRES TO BATTERY IF FAN DONT WORK REPLACE THE FAN MOTOR.IF COOLANT TEMPERATURE IS BAD REPLACE IT.BECAUSE IT CONTROLS THE FAN TURNING ON WHEN COOLANT GETS A CERTAIN TEMPERATURE.

Definately have a sensor problem...but that may not be all. You can blame the sensor issue on the idling problem. The overheating in park is likely one of 2 things, provided you have adequate coolant. #1 a sticking thermostat or a bad coolant temp sensor not activating your fan at idle. What you should do is have your diagnostic codes read in order to take care of the sensor issue. Most national parts chains such as Auto Zone or Advance will do this at no charge in hopes of selling you a sensor. Good Luck! I hope you find this to be very helpful.

A lot of different things fall into this senario.Low coolant level,air in the cooling system,and a stuck thermostat,or,a bad coolant sensor,or even a bad cooling fan relay,or the cooling fans are bad.Turn the defrost on or the ac,the cooling fans should come on if the fans,and the relay are ok,if so,replace the thermostat,and coolant sensor,and bleed the cooling system of air.

The fans are actuated by coolant temp in the radiator. It is possible to have overheated coolant in the radiator, causing the steam, and your engine not overheating...the temp sensor for your engine is reflecting the engine temp, not the temp of the coolant in the radiator. You problem could be a bad temp sensor at the radiator...not allowing the fans to come on. Good Luck! I hope you find this to be very helpful!

Check fuses, relays, the hook fan straight to batt power with jumper if fan is inop replace. If it works find your wiring problem.

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

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