Cooling Fan Control System

Cooling Fan Control:

PURPOSE
The Engine Control Module (ECM) performs ON/OFF control and LOW/HIGH speed control of the cooling fan corresponding to the vehicle speed, engine coolant temperature, air conditioning ON signal, and air conditioning pressure.

OPERATION

Air Conditioning Switch "OFF" Operation:

Air conditioning switch is "OFF"

Air Conditioning Switch "ON" (Any Mode But Off) High Pressure Switch "OFF" Operation:

Air conditioning switch is "ON" (Any mode except "OFF"), high pressure switch is "OFF".

Air Conditioning Switch "ON" (Any Mode But Off) High Pressure Switch "ON" Operation:

Air conditioning switch is "ON" (Any mode except "OFF"), high pressure switch is "ON".

- The cooling fan operates at HIGH if the self-diagnosing engine coolant temperature sensor system or ECM results in "NG."
- A/C compressor clutch will not engage if A/C system low side pressure is below 331 kPa (48 psi). Therefore, the A/C compressor clutch will not engage in cold temperatures below 10°C (50°F).