Jeep Cherokee

 Service Manual

Cooling system » Diagnosis and testing
Electric cooling fan

ELECTRIC COOLING FAN AND RELAY DIAGNOSIS

NOTE: Refer to Electrical Group 8W for electric cooling fan and relay circuit schematic.

The powertrain control module (PCM) will enter a diagnostic trouble code (DTC) in memory if it detects a problem in the auxiliary cooling fan relay or circuit.

Refer to Group 25, Emission Control Systems for correct DTC retrieval procedures.

If the electric cooling fan is inoperative, check the 15A fuse in the junction block and the 40A fuse in the Power Distribution Center (PDC) with a 12 volt test lamp or DVOM. Refer to the inside of the PDC cover for the exact location of the fuse. If fuses are o.k., refer to Group 8W for electric cooling fan and relay circuit schematic.

On-board diagnostics (OBD)

Accessory drive belt diagnosis

Preliminary checks

Radiator coolant flow check

Cooling system-testing for leaks

Viscous fan drive

Electric cooling fan

Radiator cap-to-filler neck seal-pressure relief check

Radiator cap-pressure testing

Coolant-low level aeration

Deaeration