2010 Cadillac CTS Sedan AWD V6-3.6L Page 1608
Instructions) provides an overview of each diagnostic category.
- Cooling Fan Relay 1 Control Circuit
- Cooling Fan Relays 2 and 3 Control Circuit
- Cooling Fan Relay 1 Control Circuit Low Voltage
- Cooling Fan Relay 1 Control Circuit High Voltage
- Cooling Fan Relays 2 and 3 Control Circuit Low Voltage
- Cooling Fan Relays 2 and 3 Control Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
The engine cooling fan system consists of one electrical cooling fan, a serviceable resistor module mounted in the cooling fan shroud, and three fan
relays. The relays are arranged in a series parallel (S/P) configuration that allows the engine control module (ECM) to operate the fan at low,
medium, or high speeds, depending on cooling requirements. The resistor module is a self-contained unit providing a specific resistance through
three individual 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 that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted
to ground, or shorted to a voltage by monitoring the feedback voltage. The cooling fan and fan relays receive battery voltage from the underhood
fuse block. The ground path for the operation of the cooling fan is provided at G104.
Conditions for Running the DTC
* The ignition voltage is between 10-18 volts.
* The engine speed is greater than 80 RPM.