P1491 Radiator Fan Control Relay Circuit

SYMPTOM
P-1491 RADIATOR FAN CONTROL RELAY CIRCUIT

WHEN MONITORED
With the ignition key on, battery voltage greater than 10 volts, and the PCM requests the fans to be turned on.

SET CONDITION
An open or shorted condition is detected in the radiator fan relay control circuit.

POSSIBLE CAUSES
- Fused B (+) circuit open
- Radiator fan relay output circuit, 0 volts to battery V
- Radiator fan relay ground circuit open
- Radiator fan relay defective
- Radiator fan relay control circuit short to ground
- Radiator fan motors will intermittent defect
- Radiator fan motors will observable defect
- Radiator fan relay control circuit open
- PCM defective (radiator fan motors)