2006 caravan cooling fan inop, not the relay or the Sensor or the PCm

Have the vehicle checked for DTC'S - diagnostic trouble code's if you haven't already . The vehicle has two cooling fans an three control relay's that are energized by the PCM - engine computer . Coolant temp sensor tell's the PCM engine temp.
Do you know what a wiring diagram is ? Free one's here http://www.bbbind.com/free-tsb Enter vehicle info. year make , model an engine . Under system click on engine ,then under subsystem click on cooling fans . Click the search button then the blue link. Watch this video.
Relay Driven Dual Cooling Fan Diagnostics

Also ,what are you going by to say it's overheating ? Temp gauge in the instrument cluster ? GM had problems with Stepper motors inside the instrument cluster . 2003 - 2006 . Hooking up a scan tool that can view data would show what the coolant temp sensor is tell the PCM .

Using a infered temp
This would show the real temp of the engine.

DTC P0480 or P0481
Battery positive voltage is supplied to the cooling fan 1 relay from the COOL FAN #1 fuse. The powertrain control module (PCM) controls the cooling fan 1 relay by grounding the low speed cooling fan relay control circuit via an internal solid state device called a driver.
Battery positive voltage is supplied to the cooling fan 2 relay and the cooling fan 3 relay from the COOL FAN #2 fuse. The PCM controls the relays by grounding the high speed cooling fan relay control circuit.
When the PCM is commanding a relay on, the voltage potential of the control circuit should be low, near 0 volts. When the PCM is commanding the control circuit to a relay, the voltage potential of the circuit should be high, near battery voltage. If the fault detection circuit senses a voltage other than what is expected, the DTC will set.
The PCM will monitor the control circuit for the following conditions:
• A short to ground
• A short to voltage
• An open circuit
• An open relay coil
• An internally shorted or excessively low resistance relay coil
When the PCM detects any of the above conditions, the DTC will set and the affected driver will be disabled.

I would say the instrument cluster is probably the problem . If the fans come on when A/C is turned on the system is working.

How to repair GM Instrument Cluster Speedometer Gauge Stepper

How about the water pump ? Who replaced the parts ? A qualified repair shop ? Were codes checked ?
The PCM controls the electro-viscous fan clutch engagement. The PCM regulates a 12-volt pulse width modulated signal (PWM) to the cooling fan relay. The PWM signal determines the ON time of the relay. As the commanded state of the fan clutch increases, so does the ON time of the relay. This ON time directly effects the amount of time the solenoid, which is internal to the fan clutch, is energized. When the solenoid in the fan clutch is energized, it opens the spring loaded valve and allows fluid to flow from the storage chamber to the fluid coupling of the cooling fan clutch, increasing the fan speed. When the solenoid is de-energized, the spring loaded valve closes, and blocks the path of the fluid to the fluid coupling of the fan clutch, reducing fan speed.
The fan has the ability to create a feedback signal, so the PCM has an actual fan speed input. This is done with a hall effect sensor internal to the fan clutch. The PCM supplies a 5-volt reference and a low reference to the hall effect sensor. The hall effect sensor returns a signal pulse through the cooling fan speed signal circuit in response to the relucktor track passing by the magnetic field of the hall effect sensor.
Was electrical tested before fan clutch was replaced !

there is 2 fuses that you have to check
one will be in the big fuse assembly in the engine bay, the other probably in the fuse assembly in the cab
If they prove ok then it is possible that the coolant temperature SENSOR is faulty and needs replacing
don't confuse it with the temperature sender which operates the temp gauge.

There are two relays in the integrated power module under the hood in the engine compartment , radiator fan high/low control relay an radiator fan high relay . They are controlled by the front control module . The ECT - engine coolant temperature sensor is an input to the PCM -powertrain control module , this module has logic programmed into it an when it sees a signal from the ECT ,it knows what the temp. of the engine is ! At 195 to 223 degrees the PCM commands the cooling fans on ! I won't get into the whole thing of serial data communication networking but the PCM sends a command to the module that controls the cooling fans ! You best bet is to take it to the dealer or another repair facility that has the tools an knowledge to diagnose the problem ! Aren't electronics great !

The cooling fan is controlled by the PCM - powertrain control module through a relay ! There is no cooling fan sensor , there is a coolant temperature sensor ! This coolant temperature sensor is an input to the engine computer , if there were a problem wit the sensor the check engine light would be on .
Cooling Fan Control
The engine cooling fan system consists of one cooling fan and one relay. The relay is powered by the battery positive voltage circuit and controlled by a switched ground from the powertrain control module (PCM).
During operation, the PCM supplies the ground path for the cooling fan relay through the cooling fan relay control circuit. This energizes the cooling fan relay coil, closes the relay contacts, and supplies battery positive voltage from the cooling fan fuse through the cooling fan motor supply voltage circuit to the cooling fan. The cooling fan motor is grounded through its own ground circuit.
The PCM commands the fan on under the following conditions:
?€¢
Engine coolant temperature exceeds approximately 106?°C (223?°F).

?€¢
A/C refrigerant pressure exceeds 1310 kPa (190 psi).

?€¢
A/C is requested and vehicle speed is below 100 km/h (62 mph) with A/C pressure above 1413 kPa (205 psi).

?€¢
Vehicle speed is less than 8 km/h (5 mph) for more than 750 seconds. The fan will turn off when vehicle speed is greater than 8 km/h (5 mph) for more than 20 seconds.

have you checked the fuses 1st.then what is the condition of the plug connector at the cooling fans,these sometimes go bad.then you will have to check the cooling fan relay to make sure its working also the temp sensor for the pcm that tells the computer that the fan needs to operate.finely the pcm could present a problem but rarely does.

The cooling fan is supposed to come on when the /ac compressor clutch cycles on, and off when it cycles off.
The idle speed kicks up to compensate for the additional a/c compressor load and the additional alternator load. usually, just the low speed comes on until it hits a much higher temperature.

the system should cycle 4 to 7 times/minute at 79 degrees F.

Here are some things to consider:(The PCM (engine computer) is NEVER defective, don't replace it). I don't think it is the ECT (engine coolant temp sensor) or the Cylinder Head Temp Sensor. Or the VSS or the MAF sensors.


The electronically controlled fan clutch is controlled by the powertrain control module (PCM) based upon requests for airflow to cool the engine, transmission and A/C condenser. If no cooling is required, the electronics permit the fan to spin at a slower speed yielding improved fuel economy.
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Inoperative or damaged:

• Electronically actuated fan clutch
• Electronically actuated fan clutch controller
• Wiring, connectors, relays or modules
• Engine Coolant Temperature (ECT) sensor (4.0L SOHC)
• Cylinder Head Temperature (CHT) sensor (4.6L [3V])
• Mass Air Flow (MAF) sensor
• Vehicle Speed Sensor (VSS)
• ----------------------------------------------------------------------------

If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC).
Retrieve any DTC Codes (Diagnostic Test Code). Autozone will do for free.

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The cooling fan clutch actuator valve controls the fluid flow from the reservoir into the working chamber. Once viscous fluid is in the working chamber, shearing of the fluid results in fan rotation.

The cooling fan clutch actuator valve is activated with a pulse width modulated (PWM) output signal from the powertrain control module (PCM). By opening and closing the fluid port valve, the PCM can control the cooling fan clutch speed. The cooling fan clutch speed is measured by a Hall-effect sensor and is monitored by the PCM during closed loop operation.

The PCM optimizes fan speed based on engine coolant temperature (ECT), engine oil temperature (EOT), transmission fluid temperature (TFT), intake air temperature (IAT), or air conditioning requirements. When an increased demand for fan speed is requested for vehicle cooling, the PCM monitors the fan speed through the Hall-effect sensor. If a fan speed increase is required, the PCM outputs the PWM signal to the fluid port, providing the required fan speed increase.

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Heather, the radiater fan relay is solid state, mounted behind the facia
on a bracket drivers side, right of left headlamp assembly, feed by fuse 24, 40 amp in the pdc, box, I'm assuming thats what your talking about, the coolant sensor signals the PCM ,when temp hits 212*F, tells the solid state relay to turn the fans on, check the ground for the fans, should be near the relay. if by chance you have no air lock in the cooling system, after the pump was replaced. Belt routing ok, was this done by experinced help. GOOD LUCK, RDJRP

dont think so,seem to remember a reostat somewhere at the bottom of the rad right hand side ,check for earth problems as well ,sorry if vague but i seem to be forgetting things as i get old .

P0480 Cooling Fan I Control Circuit Malfunction
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Chrysler has issued a TSB (#18-004-07)containing the fix for an inoperative cooling fan on 2005-06 Caravans and Town & Country vans with the 3.3L or 3.8L engines. The problem usually occurs after driving in heavy snow conditions where snow and ice form at the bottom of the fan shroud and block the fan blade. This condition also sets a P0480 code in the PCM. The fix requires a PCM reflash. If you have an inoperative cooling fan or a P0480 code, check the version label attached to the PCM. If a software update has not been performed since this TSB’s issue date of January 24, 2007, you should have the update performed before you start replacing any parts.