[55B] AUTOMATIC AIR CONDITIONER - - TROUBLESHOOTING - SYMPTOM PROCEDURES - INSPECTION PROCEDURE 10: Malfunction of the A/C-ECU power supply system. | PRINT PAGE / INDEX / PRIOR / NEXT

INSPECTION PROCEDURE 10: Malfunction of the A/C-ECU power supply system.
CIRCUIT OPERATION The A/C-ECU power system may be defective if the air conditioner, rear window defogger, and outside/inside air selection damper motor all do not operate normally.
TROUBLESHOOTING HINTS Damaged the wiring harness or connectors Malfunction of the A/C-ECU
| DIAGNOSIS
| Step 1. Measure the voltage at A/C-ECU connector C-26. Disconnect A/C-ECU connector C-26 and measure the voltage at the harness side. Turn the ignition switch to the "ON" position. Measure the voltage between terminal 28 and earth. OK: System voltage Q: Is the check result normal? YES: Go to Step 4. NO: Go to Step 2.
| Step 2. Connector check: A/C-ECU connector C-26 Q: Is the check result normal? YES: Go to Step 3. NO: Repair or replace the connector.
| Step 3. Check the wiring harness between A/C-ECU connector C-26 (terminal 28) and the ignition switch (IG2). NOTE: Prior to the wiring harness inspection, check junction block connectors C-205 and C-203, and repair if necessary. Q: Is the check result normal? YES: The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ). NO: Repair the wiring harness.
| Step 4. Measure the resistance at A/C-ECU connector C-26 in order to check the earth circuit to the A/C-ECU. Disconnect A/C-ECU connector C-26, and measure at the wiring harness side. Measure the resistance between terminal 27 and earth. OK: 2 ohms or less Q: Is the check result normal? YES: Go to Step 7. NO: Go to Step 5.
| Step 5. Connector check: A/C-ECU connector C-26 Q: Is the check result normal? YES: Go to Step 6. NO: Repair or replace the connector.
| Step 6. Check the wiring harness between A/C-ECU connector C-26 (terminal 27) and the earth. Q: Is the check result normal? YES: Replace the automatic air conditioner control panel (A/C-ECU). NO: Repair the wiring harness.
| Step 7. Measure the voltage at A/C-ECU connector C-27. Disconnect A/C-ECU connector C-27 and measure the voltage at the harness side. Measure the voltage between terminal 3 and earth. OK: System voltage Q: Is the check result normal? YES: Replace the automatic air conditioner control panel (A/C-ECU). NO: Go to Step 8.
| Step 8. Connector check: A/C-ECU connector C-27. Q: Is the check result normal? YES <Except vehicles for South Africa>: Go to Step 9. YES <Vehicles for South Africa>: Go to Step 10. NO: Repair or replace the connector.
| Step 9. Check the wiring harness between A/C-ECU connector C-27 (terminal 3) and battery. NOTE: Prior to the wiring harness inspection, check intermediate connector C-125, A-14 and junction block connector C-204, and repair if necessary. Q: Is the check result normal? YES: The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ). NO: Repair the wiring harness.
| Step 10. Check the wiring harness between A/C-ECU connector C-27 (terminal 3) and battery. NOTE: Prior to the wiring harness inspection, check intermediate connector C-116 and joint connector C-02, and repair if necessary. Q: Is the check result normal? YES: The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ). NO: Repair the wiring harness.

[55B] AUTOMATIC AIR CONDITIONER - - TROUBLESHOOTING - SYMPTOM PROCEDURES - INSPECTION PROCEDURE 10: Malfunction of the A/C-ECU power supply system. | PRINT PAGE / INDEX / PRIOR / NEXT

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