Corsica V6-3100 3.1L MFI VIN M (1994)
Radiator Cooling Fan Motor Relay: Description and Operation
Cooling Fan Control Circuit Diagram
The PCM controls engine cooling fan operation through a relay. The fans only operate when needed. The relays get battery voltage when the ignition is
turned "ON", and are energized when the PCM completes the relay coils circuit to ground. The PCM will operate the cooling fans under any of the
following conditions:
PRIMARY COOLING FAN
1.
A/C is requested and vehicle speed is less than 50 mph (81 km/h).
2.
Engine coolant temperature is greater than 226°F (108°C) with A/C "OFF", coolant temperature greater than 223°F (106°C) with A/C "ON".
1.
A/C refrigerant high side pressure greater than 185 psi (1275kPa).
Once the primary cooling fan is enabled, the PCM will turn it "OFF" when:
1.
The engine is turned "OFF".
2.
Engine coolant temperature drops below 210°F (99°C)
3.
Condition #2 and refrigerant high side pressure less than 189 psi (1260kPa) with A/C "ON".
NOTE: The primary cooling fan will operate continuously whenever the ignition is turned "ON" if code 14, 15, or 70 is set.
SECONDARY COOLING FAN
1.
A/C is requested and vehicle speed is less than 50 mph (81 km/h).
2.
Engine coolant temperature is greater than 235°F (113°C)
3.
A/C refrigerant high side pressure greater than 136 psi (938kPa).
Once the secondary cooling fan is enabled, the PCM will turn it "OFF" when:
1.
The engine is turned "OFF".
2.
Engine coolant temperature drops below 228°F (109°C)
3.
Condition #2 and refrigerant high side pressure less than 185 psi (1233kPa) with A/C "ON".
