2010 Cadillac Truck SRX FWD V6-3.0L Page 1524

2010 Cadillac Truck SRX FWD V6-3.0L Page 1524

Circuit/System Description

The engine cooling fan system is composed of one cooling fan, a series of 5 relays, the engine control module (ECM), and the associated wiring.

The cooling fan assembly includes two individual resistors mounted to each side of the cooling fan shroud. This combination of components

enables the ECM to operate the cooling fan at 3 speeds using two fan control circuits.

To operate the fan, the ECM activates the applicable relay by grounding the control circuit with a solid state device called a driver. The driver is

equipped with a feedback circuit. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the

feedback voltage.

Conditions for Running the DTC

* The ignition voltage is between 11-18 volts.

* The engine speed is greater than 400 RPM.

* The ECM driver transitions from ON to OFF or from OFF to ON.

* DTC P0480 runs continuously when the conditions above are met.

Conditions for Setting the DTC

P0480

The ECM detects an open circuit, short to ground, or a short to voltage on the cooling fan relay control circuit, for greater than 200 mS.

Action Taken When the DTC Sets

DTC P0480 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0480 is a Type B DTC.

Diagnostic Aids

* A condition with the powertrain relay or the bussed ignition voltage circuit to the cooling fan relay may set this DTC.

* The ECM has the capability of providing command to the fan relays even when a scan tool output control is being used. Always refer to the

scan tool Cooling Fan Relay Command parameters to know which fans are being commanded ON by the ECM.

* The scan tool cooling fan output control operates as follows:

- Cooling Fan Relay 1 operates the fan at a low speed

- Cooling Fan Relay 2 and 3 operates the fan at a medium speed