Inspection Procedure 9: AS&G-ECU Power Supply, Ignition Switch-IG1 System


OPERATION



  • The power voltage is supplied to the AS&G-ECU (terminal No. 13) from the engine control relay (terminal No. 2).
  • The ignition switch-IG1 signal is inputted into the AS&G-ECU (terminal No. 30) from the ETACS-ECU (terminal No. 10).
  • The AS&G-ECU (terminal No. 15) is earthed to the vehicle body.

PROBABLE CAUSES



  • Open/short circuit or harness damage in engine control relay circuit, or loose connector contact
  • Open/short circuit or harness damage in ignition switch-IG1 circuit, or loose connector contact
  • Open circuit or harness damage in AS&G-ECU earth circuit, or loose connector contact
  • Failed AS&G-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-11 AS&G-ECU connector

Q. Is the check result normal?
Go to Step 2.
Repair or replace the connector.

STEP 2. Perform voltage measurement at C-11 AS&G-ECU connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 13 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 4.

    Go to Step 3.

STEP 3. Connector check: A-37X engine control relay connector

Q. Is the check result normal?

    Check and repair harness between A-37X (terminal No. 2) engine control relay connector and C-11 (terminal No. 13) AS&G-ECU connector.

    • Check power supply line for open/short circuit.

    Repair or replace the connector.

STEP 4. Perform voltage measurement at C-11 AS&G-ECU connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 30 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 12.
Go to Step 5.

STEP 5. Perform voltage measurement at C-417 ETACS-ECU connector by back probing.

  • Do not disconnect connector.
  • Ignition switch: ON
  • Voltage between terminal No. 6 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 10.
NO <Vehicles without OSS> : Go to Step 6.
NO <Vehicles with OSS> : Go to Step 8.

STEP 6. Connector check: C-309 ignition switch connector and C-417 ETACS-ECU connector


Q. Are the check results normal?
Go to Step 7.
Repair or replace the connector.

STEP 7. Check ignition switch itself.

  • Check ignition switch itself (Refer to GROUP 54A - Ignition Switch - Inspection - Ignition Switch Check ).

Q. Is the check result normal?

    Check and repair harness between C-309 (terminal No. 2) ignition switch connector and C-417 (terminal No. 6) ETACS-ECU connector.

    • Check power supply line for open/short circuit and damage.
Replace the ignition switch.

STEP 8. Connector check: C-14 OSS-ECU connector and C-417 ETACS-ECU connector

Q. Are the check results normal?
Go to Step 9.
Repair or replace the connector.

STEP 9. Check harness between C-14 (terminal No. 7) OSS-ECU connector and C-417 (terminal No. 6) ETACS-ECU connector.

  • Check power supply line for open/short circuit.

Q. Is the check result normal?
Perform the troubleshooting of the OSS-ECU (Refer to GROUP 42B - Troubleshooting <OSS-ECU> - Symptom Chart ).
Repair the damaged harness wire.

STEP 10. Connector check: C-403 and C-417 ETACS-ECU connectors

Q. Are the check results normal?
Go to Step 11.
Repair or replace the connector.

STEP 11. Continuity check on C-403 and C-417 ETACS-ECU connectors.

  • Disconnect connectors, and check at ETACS-ECU side.
  • Continuity check between terminal No. 6 (C-417) and terminal No. 10 (C-403).
note Connect the (+) side of circuit tester to terminal No. 10.
OK: Continuity

Q. Is the check result normal?

    Check and repair harness between C-403 (terminal No. 10) ETACS-ECU connector and C-11 (terminal No. 30) AS&G-ECU connector.

    • Check power supply line for open/short circuit.
Replace the ETACS-ECU.

STEP 12. Perform resistance measurement at C-11 AS&G-ECU connector.

  • Disconnect connector, and measure at harness side.
  • Resistance between terminal No. 15 and earth.
OK: Continuity (2 Ω or less)

Q. Is the check result normal?
Go to Step 13.

    Check and repair harness between C-11 (terminal No. 15) AS&G-ECU connector and body earth.

    • Check earthing line for open circuit and damage.

STEP 13. Connector check: C-403 and C-417 ETACS-ECU connectors

Q. Are the check results normal?
Go to Step 14.
Repair or replace the connector.

STEP 14. Continuity check on C-403 and C-417 ETACS-ECU connectors

  • Disconnect connectors, and check at ETACS-ECU side.
  • Continuity check between terminal No. 6 (C-417) and terminal No. 10 (C-403).
note Connect the (+) side of circuit tester to terminal No. 10.
OK: Continuity

Q. Is the check result normal?
Go to Step 15.
Replace the ETACS-ECU.

STEP 15. Check harness between C-403 (terminal No. 10) ETACS-ECU connector and C-11 (terminal No. 30) AS&G-ECU connector.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 16.
Repair the damaged harness wire.

STEP 16. Connector check: A-37X engine control relay connector

Q. Is the check result normal?
Go to Step 17.
Repair or replace the connector.

STEP 17. Check harness between A-37X (terminal No. 2) engine control relay connector and C-11 (terminal No. 13) AS&G-ECU connector.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 18.
Repair the damaged harness wire.

STEP 18. Check the trouble symptom.

Q. Does the trouble symptom persist?
Replace the AS&G-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).