GM > System > Fans

Fan Type

• Number of Fans Fitted: Number of engine cooling fans fitted to the vehicle.
• 2 Fans: Vehicles equipped with 2 fans.
• Aux Fans: Vehicles equipped with Auxiliary fans.
• No Fans: Vehicle is equipped with no fans.
• Series/Parallel: Vehicle is equipped with relay controlled series/parallel fans.
• Variable Speed: Vehicle is equipped with electronically controlled variable speed electric fans.
• Electro Viscous: Vehicle is equipped with electronically controlled viscous coupled fans.

  
  

• Discrete: Vehicles equipped with relay controlled fans.
• PWM Electric: Vehicles equipped with electronically controlled variable speed electric fans
• PWM EV: Vehicles equipped with electro-viscous fan.

Fan Stage 1

• On: Temperature at which this fan stage should activate.
• Off: If activated, temperature at which this fan stage should de-activate.
• Min Speed:
• Max Speed:

Fan Stage 2

• On: Temperature at which this fan stage should activate.
• Off: If activated, temperature at which this fan stage should de-activate.

Ignition Off Fan

• Disable Temp: Temperature at which the fans will switch off after ignition off
• Run Time: Maximum Fan run time after ignition off if Disable Temp exceeded
• Run Time Zone: Selects which zone is used for disable ECT threshold checking based on fan run time
• ETC Zone: Minimum ECT to disable ignition off fans in relation to run time zone
• ETC Zone High: Minimum ECT to disable high speed ignition off fans in relation to run time zone
• Enable ECT A:
• Disable ECT:
• High Enable ECT: Above this ECT, high speed ignition off fan mode is enabled
• High Disable ECT: Below this ECT, high speed ignition off fan mode is disabled
• Fan %: Commanded FAN percent for ignition off fan
• Fan High %: Commanded FAN percent for high speed ignition off fan

Fan Desired %

• Desired % vs. ECT: The desired percent that fans should operate in regards to coolant temperature.
• Desired % vs. AC Pressure: The desired percent that fans should operate in regards to AC pressure.

Fan Relay Controls (Series/Parallel/Discrete - selected vehicles only)

• State vs. Desired %: Selects the current state of series/parallel/discrete fan operation based on Desired %.
• Output Control vs. State: Selects which of 3 outputs are active for any given state. A value of 1 means the output is active and 0 is inactive.

Climate Control Fans Override

• Yes: Climate control system (if fitted) controls Fan operation
• No: PCM controls Fan operation