Cooling Fan – V8

When the ATC ECU engages the A/C compressor clutch, the ATC ECU (C1629) informs the ECM (C0331) via the K bus on a WRY wire that cooling fan operation is required. The ATC ECU also informs the ECM of the speed to drive the motor. For more information on A/C operation, refer to the Automatic Temperature Control (ATC) or Automatic Temperature Control (ATC) – Comfort section of this manual.  AUTOMATIC TEMPERATURE CONTROL (ATC).  AUTOMATIC TEMPERATURE CONTROL (ATC) – COMFORT.

The ECM (C0331) now provides a feed to the cooling fan control unit (C0005) on a BG wire. This is used by the control unit to regulate the supply voltage from maxi fuse 61 of the passenger compartment fuse box (C0581) on an RU wire.

Cooling Fan – V8

Operation of the cooling fan is controlled by the ECM. The ECM also monitors Engine Coolant Temperature (ECT) to determine fan speed. The ECM (C0606) provides a feed to the ECT sensor (C0169) on a YG wire. The ECT sensor is a Negative Temperature Coefficient (NTC) sensor. By measuring the voltage returned on an NO wire, the ECM can determine engine coolant temperature.

When the ATC ECU engages the Air Conditioning (A/C) compressor clutch, the ATC ECU (C1629) informs the ECM (C0331) via the K bus on a WRY wire that cooling fan operation is required. The ATC ECU also informs the ECM of the speed to drive the motor. For more information on A/C operation, refer to the Automatic Temperature Control (ATC) or Automatic Temperature Control (ATC) – Comfort section of this manual.  AUTOMATIC TEMPERATURE CONTROL (ATC).  AUTOMATIC TEMPERATURE CONTROL (ATC) – COMFORT.

The ECM (C0331) now provides a feed to the cooling fan control unit (C0005) on a BG wire. This is used by the control unit to regulate the supply voltage from maxi fuse 61 of the passenger compartment fuse box (C0581) on an RU wire.