IC pump and radiator fan not working

[JB_2010GT500]

Tried searching the forums already. Very odd that both will not turn on when the motor is running. I can jumper both the IC pump and radiator fan and they will run just fine. The relays all look good. Tried turning AC on various settings and I could not get the pump nor fan to turn on. Did some data logging of the fan speed commands and got coolant up to 230*. Looked at the logs and the fan was never commanded to start.

Is there some sort of temperature switch/sensor which commands both the fan and IC pump? I'm thinking that either the PCM doesn't know the motor is running, which is why the components are not being commanded to start, or there is a common switch or sensor shared by both components that is out of order. Also, I am not seeing any DTC codes. Any ideas would be greatly appreciated.

Thanks in advance!

 

[Snoopy49]

Electric Cooling Fan
The electric cooling fan is an electrically actuated viscous clutch that consists of 3 main elements:
• a working chamber
• a reservoir chamber
• a cooling fan clutch actuator valve and a fan speed sensor (FSS)
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 PCM. By opening and closing the fluid port valve, the PCM can control the electric
cooling fan speed. The electric cooling fan 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.

Engine Coolant Temperature (ECT) Sensor
The ECT sensor is a thermistor device in which resistance changes with temperature. The
electrical resistance of a thermistor decreases as the temperature increases, and the resistance
increases as the temperature decreases. The varying resistance changes the voltage drop across
the sensor terminals and provides electrical signals to the PCM corresponding to temperature.
Thermistor-type sensors are considered passive sensors. A passive sensor is connected to a
voltage divider network so varying the resistance of the passive sensor causes a variation in total
current flow. Voltage that is dropped across a fixed resistor (pull-up resister) in series with the
sensor resistor determines the voltage signal at the PCM. This voltage signal is equal to the
reference voltage minus the voltage drop across the fixed resistor.
The ECT measures the temperature of the engine coolant. The PCM uses the ECT input for fuel
control and for cooling fan control. There are 3 types of ECT sensors; threaded, push-in, and
twist-lock. The ECT sensor is located in an engine coolant passage.

Charge Air Cooler (CAC) System
The CAC system cools the intake air which has been heated by the supercharger. The removal of
heat from the pressurized air going into the CAC increases the air density which improves
combustion efficiency, engine horsepower, and torque. The system consists of an additional CAC
radiator in the grille, a reservoir (independent from the engine cooling system), an electric water
pump, the CAC located in the lower intake manifold, and tubing to interconnect these components.
The CAC is positioned after the supercharger directly in the flow of the intake air. As the heated
air flows through the CAC, heat is transferred to the coolant which is circulated back to the CAC
radiator to be cooled by the airflow through the grille. The CAC pump is controlled by the
powertrain control module (PCM). The PCM maintains a desirable intake air temperature by
monitoring a second intake air temperature (IAT2) sensor in the lower intake manifold.

 

[fauls gt500]

Tried searching the forums already. Very odd that both will not turn on when the motor is running. I can jumper both the IC pump and radiator fan and they will run just fine. The relays all look good. Tried turning AC on various settings and I could not get the pump nor fan to turn on. Did some data logging of the fan speed commands and got coolant up to 230*. Looked at the logs and the fan was never commanded to start.

Is there some sort of temperature switch/sensor which commands both the fan and IC pump? I'm thinking that either the PCM doesn't know the motor is running, which is why the components are not being commanded to start, or there is a common switch or sensor shared by both components that is out of order. Also, I am not seeing any DTC codes. Any ideas would be greatly appreciated.

Thanks in advance!

check the plug at the fan they melt sometimes

 

[JB_2010GT500]

Figured it out. It was a blown fuse (#46 PCM vehicle power 3 - general powertrain components). Funny how just a 5 amp fuse could cause both the IC pump and radiator fan to not come on. Thanks for the replies guys.


Sent from my iPhone using Tapatalk

 

[Papaw]

Glad you found it, and that it was such an easy fix.

 

[Snoopy49]

That's the control fuse for a couple of different components. It's supplies voltage to the coil on the relays.

Fuse #46 Battery Junction Box
A/C Relay, Charge Air Cooler Pump Relay, Heated PCV Valve, High Speed Engine Fan Relay, Low Speed Engine Fan Relay, Transmission Shift Selector.

 

[ShelbyGT5HUN]

I have found that fuses can blow, just due to age, and not because of a current overload. It's more common on higher amperage circuits though. It doesn't take much to pop an old 5A one. +1 for the easy fix!

 

[JB_2010GT500]

Thanks for the info on fuse #46, snoopy!