Part 2 of 2
Chart C-12 Part 2 Of 2:
Cooling Fan Control:
CIRCUIT DESCRIPTION
Battery voltage to operate secondary cooling fan (#2) motor is supplied to secondary cooling fan (#2) relay by CKT 1442. Ignition voltage to energize secondary cooling fan (#2) relay is supplied by CKT 241. When the A/C compressor clutch is energized by selecting "A/C" or "Defrost," the relay is energized and the secondary cooling fan #2) is turned "ON.
When the engine is running, the PCM will turn the secondary cooling fan (#2) "ON," for any one of the following reasons:
^ Engine Coolant Temperature (ECT) sensor indicating a temperature greater than 113°C (235°F) with A/C "OFF" or "ON".
^ A/C is requested and vehicle speed is less than 50 mph (81 km/h).
^ A/C refrigerant pressure sensor is open [pressure greater than 136 psi (938 kPa)]
Once the secondary cooling fan (#2) is enabled, the PCM will turn the secondary cooling fan (#2) "OFF" when:
^ Engine is turned "OFF."
OR
^ When the ECT sensor indicates the coolant temperature has dropped to 109°C (228°F) or less.
OR
^ When the A/C pressure drops to 185 psi or less.
DIAGNOSTIC AIDS:
If the owner comments about poor A/C cooling, it must be determined whether a low A/C refrigerant charge is the cause, or DTC 66 or 70 is set, or the secondary cooling fan (#2) is faulty.