Inspection Procedure 20: Intake Air Control Flap System














OPERATION




FUNCTION




PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. Connector check: B-02-1 intake air control flap connector


Q. Is the check result normal?

Go to Step 2 .
Repair or replace the connector.

STEP 2. Connector check: B-05 engine-ECU connector


Q. Is the check result normal?

Go to Step 3 .
Repair or replace the connector.

STEP 3. Check harness between B-02-1 (terminal No. 1) intake air control flap connector and B-05 (terminal No. 40) engine-ECU connector.


note Before checking harness, check intermediate connector B-02, and repair if necessary

  • Check output line for open/short circuit and damage.

Q. Is the check result normal?

Go to Step 4 .
Repair the damaged harness wire.

STEP 4. Perform resistance measurement at B-02-1 intake air control flap.



  • Disconnect connector, and measure at the harness side.
  • Resistance between terminal No. 4 and earth.
OK: 2 Ω or less

Q. Is the check result normal?

Go to Step 5 .

    Check intermediate connectors A-13 and B-02, and repair if necessary. If intermediate connectors are normal, check harness between the B-02-1 (terminal No. 4) intake air control flap connector and body earth.

    • Check earthing line for open circuit and damage.

STEP 5. Connector check: A-21X intake air control flap relay connector


Q. Is the check result normal?

Go to Step 6 .
Repair or replace the connector.

STEP 6. Check intake air control flap relay itself.



  • Check intake air control flap relay itself (Refer to ).

Q. Is the check result normal?

Go to Step 7 .
Replace the intake air control flap relay.

STEP 7. Perform voltage measurement at A-21X intake air control flap relay connector.



  • Pull out relay and measure at connector side.
  • Voltage between terminal No. 4 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 8 .

    Check and repair harness between battery and A-21X (terminal No. 4) intake air control flap relay connector.

    • Check power supply line for open/short circuit.

STEP 8. Perform resistance measurement at A-21X intake air control flap relay connector.



  • Remove relay, and measure at relay box side.
  • Resistance between terminal No. 1 and earth.
OK: 2 Ω or less

Q. Is the check result normal?

Go to Step 9 .

    Check and repair harness between A-21X (terminal No. 1) intake air control flap relay connector and body earth.

    • Check earthing line for open circuit and damage.

STEP 9. Perform voltage measurement at A-21X intake air control flap relay connector.



  • Pull out relay and measure at connector side.
  • Ignition switch: ON
  • Voltage between terminal No. 2 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 11 .
Go to Step 10 .

STEP 10. Connector check: A-33X engine control relay connector


Q. Is the check result normal?


    Check and repair harness between A-33X (terminal No. 2) engine control relay connector and A-21X (terminal No. 2) intake air control flap relay connector.

    • Check power supply line for open/short circuit.
Repair or replace the connector.

STEP 11. Perform voltage measurement at B-02-1 intake air control flap connector.



  • Disconnect connector, and measure at the harness side. Connect the terminal No. 131 of the engine-ECU harness connector to the earth.
  • Ignition switch: ON
  • Voltage between terminal No. 3 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 13 .
Go to Step 12 .

STEP 12. Check harness between A-21X (terminal No. 3) intake air control flap relay connector and B-02-1 (terminal No. 3) intake air control flap connector.


note Before checking harness, check intermediate connectors A-13 and B-02, and repair if necessary

  • Check output line for open/short circuit.

Q. Is the check result normal?


    Check harness between the A-33X (terminal No. 2) engine control relay connector and A-21X (terminal No. 2) intake air control flap relay connector.

    • Check power supply line for damage.
Repair the damaged harness wire.

STEP 13. Check harness between battery and A-21X (terminal No. 4) intake air control flap relay connector.



  • Check power supply line for damage.

Q. Is the check result normal?

Go to Step 14 .
Repair the damaged harness wire.

STEP 14. Check harness between A-21X (terminal No. 3) intake air control flap relay connector and B-02-1 (terminal No. 3) intake air control flap connector.


note Before checking harness, check intermediate connector B-02, and repair if necessary

  • Check power supply line for damage.

Q. Is the check result normal?

Go to Step 15 .
Repair the damaged harness wire.

STEP 15. Check harness between B-02-1 (terminal No. 2) intake air control flap connector and B-05 (terminal No. 15) engine-ECU connector.


note Before checking harness, check intermediate connector B-02, and repair if necessary

  • Check output line for open/short circuit and damage.

Q. Is the check result normal?

Go to Step 16 .
Repair the damaged harness wire.

STEP 16. Replace the intake air control flap.



  • After replacing the intake air control flap, re-check the trouble symptoms.

Q. Does trouble symptom persist?

Go to Step 17 .
The check is end.

STEP 17. Check the trouble symptoms.


Q. Does trouble symptom persist?

Replace the engine-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).