High Speed Radiator Fan Control Relay Circuit

Code Number
Scan tool 139
General scan tool P1487
MIL 35

Description
High Speed Radiator Fan Control Relay Circuit

Probable Cause
- Relay coil open or shorted
- Ignition switch output circuit open
- Low speed radiator fan relay control circuit open or shorted
- PCM failed

Background
- The high speed radiator fan relay controls the high speed operation of the radiator fan.
- One side of the relay control coil is supplied with 12 volts when the ignition switch is turned to the ON position.
- The circuit' is completed when the other side of the relay coil is grounded by the PCM.
- The PCM grounds the relay control circuit depending on engine coolant temperature and or A/C compressor condition, etc,

Range of Check
- Battery voltage: 10 V or more
- Ignition switch: ON

Set Condition
- An open or shorted condition is detected in the high speed radiator fan relay control circuit for 3 seconds.





Diagnosis