INSPECTION
PROCEDURE 6: The A/C compressor does not work
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COMMENTS ON TROUBLE SYMPTOM
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When the A/C compressor does not work, the A/C compressor circuit system
may be defective.
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- Malfunction of the A/C compressor
- Malfunction of the A/C compressor relay
- Damaged harness wires or connectors
- Malfunction of the engine-ECU
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STEP 1. M.U.T.-III CAN bus diagnostics
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Use the M.U.T.-III to diagnose the CAN bus lines.
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Q.
Is the check result normal?
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 Go to Step 2.
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 Repair the CAN bus lines. (Refer to GROUP 54C - Troubleshooting  ).
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STEP 2. M.U.T.-III diagnosis code
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Check whether the A/C sets a diagnosis code or not.
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Q.
Is the check result normal?
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Go to Step 3.
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Refer to diagnosis code chart .
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STEP 3. Voltage measurement at A/C compressor assembly connector.
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(1)Disconnect the connector, and measure at the wiring harness side.
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(2)Turn the ignition switch to the "ON" position.
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(3)Disconnect engine-ECU connector and earth terminal 102.
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(4)Voltage between terminal 1 and body earth.
OK: System voltage
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Q.
Is the check result normal?
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Go to Step 4.
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Go to Step 8.
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STEP 4. Check the A/C compressor.
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Refer to .
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Q.
Is the check result normal?
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Go to Step 5.
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Replace the A/C compressor.
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STEP 5. Check the refrigerant temperature switch.
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Refer to .
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Q.
Is the refrigerant temperature switch operating properly?
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Go to Step 6.
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Replace the refrigerant temperature switch.
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STEP 6. Check the refrigerant level.
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Refer to .
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Q.
Is the refrigerant level correct?
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Go to Step 7.
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Correct the refrigerant level (Refer to On-vehicle Service ).
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STEP 7. Replace the A/C-ECU, and then recheck the trouble
symptom
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Check that the compressor works normally.
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Q.
Is the check result normal?
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This diagnosis is complete.
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Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU <4B1>
and GROUP 13B - Engine-ECU <6B3>.
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STEP 8. Check the A/C compressor relay
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Refer to .
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Q.
Is the check result normal?
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Go to Step 9.
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Replace the A/C compressor relay.
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STEP 9. Voltage measurement at A/C compressor relay connector.
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(1)Remove the relay, and measure at the relay block side.
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(2)Voltage between terminal 1, 4 and body earth.
OK: System voltage
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Q.
Is the check result normal?
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Go to Step 11.
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Go to Step 10.
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STEP 10. Check of open circuit in A/C compressor relay power supply
line between fusible link and A/C compressor relay connector.
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Q.
Is the check result normal?
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The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope
with Intermittent Malfunction ).
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Repair the wiring harness.
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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.
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Q.
Is the check result normal?
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Go to Step 12.
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Repair the connector(s) or wiring harness.
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STEP 12. Check of open circuit in AC/R line (engine-ECU) between A/C
compressor relay connector and engine-ECU connector.
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Q.
Is the check result normal?
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The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope
with Intermittent Malfunction ).
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Repair the connector(s) or wiring harness.
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