P1489 High Speed Fan Control Relay Circuit
NAME OF CODEHigh Speed Fan Ctrl Relay Circuit
WHEN MONITORED
With the ignition key on and battery voltage greater than 10 volts.
SET CONDITION
An open or shorted condition is detected in the high speed radiator fan relay control circuit.
THEORY OF OPERATION
The high speed radiator fan relay controls the high speed operation of the radiator fan. When the vehicle is equipped with a power distribution center (PDC), the high speed radiator fan relay is inside the PDC. One side of the relay control coil is supplied with 12 volts when the ignition switch is in the "run" position. The circuit is completed when the other side of the relay coil is grounded by the powertrain control module (PCM). The PCM will actuate the relay when the coolant temperature reaches approximately 214°F and turn off the relay when the coolant temperature drops to approximately 208°F.
POSSIBLE CAUSE
- Relay coil open or shorted
- Fused ignition switch output circuit open
- High speed radiator fan relay control circuit open or shorted
- Inoperative circuit driver in powertrain control module