Inspection Procedure 27

A/C Condenser Fan Circuit:

Connectors:

CIRCUIT OPERATION
- The PCM sends a duty signal to the fan controller according to engine coolant temperature, vehicle speed, and the condition of the A/C switch. (The closer the average voltage at the terminal comes to five volts, the higher the fan speed becomes.)

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Malfunction of the fan motor relay.
- Malfunction of the fan motor.
- Improper connector contact, open or shortcircuited harness wire.
- PCM failed.

DIAGNOSIS




STEP 1. Check harness connector D-107 at PCM for damage.

Q: Is the harness connector in good condition?

YES: Go to Step 2.

NO: Repair or replace it. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.




STEP 2. Check the output voltage at PCM harness side connector D-107.

1. Disconnect the connector D-107 and measure at the harness side.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal 18 and ground.
- Voltage should be battery positive voltage.

4. Check the condenser fan condition.
- When the terminal 18 is disconnected, the fan should Step.
- When the terminal 18 is grounded by the jumper cable, the fan should run.

5. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the voltage and fan condition normal?

YES: Replace the PCM. Then confirm that the malfunction symptom is eliminated.

NO: Refer to Introduction To Heater, Air Conditioning And Ventilation Diagnosis.