INSPECTION PROCEDURE 6: The A/C compressor does not work
|
|
COMMENTS ON TROUBLE SYMPTOM
|
|
|
When the A/C compressor does not work, the A/C compressor circuit system may be defective.
|
|
|
- Malfunction of the A/C compressor
- Malfunction of the A/C compressor relay
- Damaged harness wires or connectors
- Malfunction of the engine-ECU
|
|
|
STEP 1. M.U.T.-III CAN bus diagnostics
|
|
|
Use the M.U.T.-III to diagnose the CAN bus lines.
|
|
|
Q.
Is the check result normal?
|
|
|
 Go to Step 2.
|
|
|
|
|
|
 Repair the CAN bus lines. (Refer to GROUP 54C - Troubleshooting  ).
|
|
|
|
|
|
STEP 2. M.U.T.-III diagnosis code
|
|
|
Check whether the A/C sets a diagnosis code or not.
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 3.
|
|
|
|
|
|
Refer to diagnosis code chart.
|
|
|
|
|
|
STEP 3. Voltage measurement at A/C compressor assembly connector.
|
|
|
(1)Disconnect the connector, and measure at the wiring harness side.
|
|
|
(2)Connect the AC/R terminal of the engine-ECU to body earth.
|
|
|
(3)Voltage between power supply terminal and body earth.
OK: System voltage
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 4.
|
|
|
|
|
|
Go to Step 8.
|
|
|
|
|
|
STEP 4. Check the A/C compressor.
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 5.
|
|
|
|
|
|
Replace the A/C compressor.
|
|
|
|
|
|
STEP 5. Check the refrigerant temperature switch.
|
|
|
Q.
Is the refrigerant temperature switch operating properly?
|
|
|
Go to Step 6.
|
|
|
|
|
|
Replace the refrigerant temperature switch.
|
|
|
|
|
|
STEP 6. Check the refrigerant level.
|
|
|
Q.
Is the refrigerant level correct?
|
|
|
Go to Step 7.
|
|
|
|
|
|
Correct the refrigerant level (Refer to On-vehicle Service).
|
|
|
|
|
|
STEP 7. Recheck the trouble symptom
|
|
|
Check that the compressor works normally.
|
|
|
Q.
Is the check result normal?
|
|
|
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction).
|
|
|
|
|
|
Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU <4B1>, GROUP 13B - Engine-ECU <6B3> and GROUP 13D - Engine-ECU <4N1>).
|
|
|
|
|
|
STEP 8. Check the A/C compressor relay
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 9.
|
|
|
|
|
|
Replace the A/C compressor relay.
|
|
|
|
|
|
STEP 9. Voltage measurement at A/C compressor relay connector.
|
|
|
(1)Remove the relay, and measure at the relay box side.
|
|
|
(2)Voltage between power supply terminal and body earth.
OK: System voltage
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 11.
|
|
|
|
|
|
Go to Step 10.
|
|
|
|
|
|
STEP 10. Check of open circuit in A/C compressor relay power supply line between fusible link and A/C compressor relay connector.
|
|
|
Q.
Is the check result normal?
|
|
|
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction).
|
|
|
|
|
|
Repair the wiring harness.
|
|
|
|
|
|
STEP 11.Check of open circuit in A/C compressor relay power supply line between A/C compressor relay connector and A/C compressor assembly connector.
|
|
|
| note |
Prior to the wiring harness inspection, check intermediate connector and repair if necessary.
|
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 12.
|
|
|
|
|
|
Repair the connector(s) or wiring harness.
|
|
|
|
|
|
STEP 12. Check of open circuit in AC/R line (engine-ECU) between A/C compressor relay connector and engine-ECU connector.
|
|
|
| note |
Prior to the wiring harness inspection, check intermediate connector and repair if necessary <4N1>.
|
|
|
|
Q.
Is the check result normal?
|
|
|
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction).
|
|
|
|
|
|
Repair the connector(s) or wiring harness.
|
|
|
|