Inspection Procedure 28
INSPECTION PROCEDURE 28: Fans (radiator fan, A/C condenser fan) are inoperative.Radiator Fan, A/C Condenser Fan Circuit:
Connectors:
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 CASE: )
- Malfunction of the fan motor relay.
- Malfunction of the fan motor.
- Improper connector contact, open or short-circuited harness wire.
- ECM
DIAGNOSIS
STEP 1. Check connector C-111 at ECM
Q: Is the 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. Measure the output voltage at ECM harness side connector C-111
1. Disconnect the connector C-111
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal No. 18 and ground.
- Voltage should be between 4.8 and 5.2 volts. (Fan rotates at high speed.)
4. Connect a jumper cable between terminal No. 18 and ground.
- The fan should stop.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage and fan condition normal?
YES: Replace the ECM or PCM. Then confirm that the malfunction symptom is eliminated.
NO: Go to Step 3.
STEP 3. Check for open circuit and short circuit to ground and harness damage between fan controller A-30 (terminal No. 2) and ECM connector C-111 (terminal No. 18)
NOTE: Check harness after checking intermediate connector C-06. If intermediate connector is damaged, repair or replace them. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
Q: Is the harness wire in good condition?
YES: Refer to Engine Cooling Diagnosis-Symptom Chart.
NO: Repair it. Then confirm that the malfunction symptom is eliminated.