Inspection Procedure 20: Engine-ECU <M/T> or engine-A/T-ECU <A/T> power supply, engine control relay, ignition switch-IG1 system












OPERATION



FUNCTION



PROBABLE CAUSE



DIAGNOSIS PROCEDURE

STEP 1. Check battery voltage.

  • Measure battery voltage during cranking.
OK: 8 V or more

Q. Is the check result normal?
Go to Step 2 .
Check battery (Refer to GROUP 54A - Battery - On-vehicle Service - Battery test ).

STEP 2. Connector check: B-15X engine control relay connector

Q. Is the check result normal?
Go to Step 3 .
Repair or replace the connector.

STEP 3. Check engine control relay.

  • Check engine control relay (Refer to ).

Q. Is the check result normal?
Go to Step 4 .
Replace the engine control relay.

STEP 4. Perform voltage measurement at B-15X engine control relay connector.

  • Remove relay, and measure at relay box side.
  • Voltage between terminal No. 2 and earth, also between terminal No. 3 and earth.
OK: System voltage

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

    Check intermediate connector A-03 <L. H. drive vehicles> or D-137 <R. H. drive vehicles>, and repair if necessary. If intermediate connector is normal, check and repair harness between B-15X (terminal No. 2 and terminal No. 3) engine control relay connector and battery.

    • Check power supply line for open/short circuit.

STEP 5. Connector check: D-244 engine-ECU <M/T> connector or D-214 engine-A/T-ECU <A/T> connector

Q. Is the check result normal?
Go to Step 6 .
Repair or replace the connector.

STEP 6. Perform voltage measurement at D-244 engine-ECU <M/T> connector or D-214 engine-A/T-ECU <A/T> connector.

  • Measure engine-ECU <M/T> or engine-A/T-ECU <A/T> terminal voltage.
  • Ignition switch: ON
  • Voltage between terminal No. 34 and earth, also between terminal No. 43 and earth.
OK: System voltage

Q. Is the check result normal?

    Check and repair harness between B-15X (terminal No. 4) engine control relay connector and D-244 (terminal No. 57) engine-ECU <M/T> connector or D-214 (terminal No. 57) engine-A/T-ECU <A/T> connector.

    • Check signal line for short circuit.
Go to Step 7 .

STEP 7. Check harness between B-15X (terminal No. 1) engine control relay connector and D-244 (terminal No. 34 and No. 43) engine-ECU <M/T> connector or D-214 (terminal No. 34 and No. 43) engine-A/T-ECU <A/T> connector.
note Before checking harness, check intermediate connector C-111, and repair if necessary.

  • Check power supply line for open/short circuit and damage.

Q. Is the check result normal?
Go to Step 8 .
Repair the damaged harness wire.

STEP 8. Perform voltage measurement at D-244 engine-ECU <M/T> connector or D-214 engine-A/T-ECU <A/T> connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 50 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 11 .
Go to Step 9 .

STEP 9. Connector check: D-309 ignition switch connector

Q. Is the check result normal?
Go to Step 10 .
Repair or replace the connector.

STEP 10. Check ignition switch.

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

Q. Is the check result normal?

    Check intermediate connectors D-231, D-403 and D-405, and repair if necessary. If intermediate connector is normal, check and repair harness between D-309 (terminal No. 2) ignition switch connector and D-244 (terminal No. 50) engine-ECU <M/T> connector or D-214 (terminal No. 50) engine-A/T-ECU <A/T> connector

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

STEP 11. Perform voltage measurement at D-244 engine-ECU <M/T> connector or D-214 engine-A/T-ECU <A/T> connector.

  • Disconnect connector, and measure at harness side.
  • Voltage between terminal No. 58 and earth.
OK: System voltage

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

    Check intermediate connector A-03 <L. H. drive vehicles> or D-137 <R. H. drive vehicles> and repair if necessary. If intermediate connector is normal, check and repair harness between D-244 (terminal No. 58) engine-ECU <M/T> connector or D-214 (terminal No. 58) engine-A/T-ECU <A/T> connector and battery.

    • Check power supply line for short circuit.

STEP 12. Check harness between B-15X (terminal No. 4) engine control relay connector and D-244 (terminal No. 57) engine-ECU <M/T> connector or D-214 (terminal No. 57) engine-A/T-ECU <A/T> connector.

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 13 .
Repair the damaged harness wire.

STEP 13. Check harness between B-15X (terminal No. 2 and No. 3) engine control relay connector and battery.
note Before checking harness, check intermediate connector A-03 <L. H. drive vehicles> or D-137 <R. H. drive vehicles>, and repair if necessary.

  • 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 D-309 (terminal No. 2) ignition switch connector and D-244 (terminal No. 50) engine-ECU <M/T> connector or D-214 (terminal No. 50) engine-A/T-ECU <A/T> connector.
note Before checking harness, check intermediate connectors D-231, D-403 and D-405, and repair if necessary.

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 15 .
Repair the damaged harness wire.

STEP 15. Connector check: D-14 earth connector.

Q. Is the check result normal?

    Check and repair harness between D-244 engine-ECU <M/T> connector or D-214 engine-A/T-ECU <A/T> connector and D-14 earth connector.

    1. Check and repair harness between D-244 (terminal No. 33) engine-ECU <M/T> connector or D-214 (terminal No. 33) engine-A/T-ECU <A/T> connector and D-14 (terminal No. 2) earth connector.
    2. Check and repair harness between D-244 (terminal No. 42) engine-ECU <M/T> connector or D-214 (terminal No. 42) engine-A/T-ECU <A/T> connector and D-14 (terminal No. 1) earth connector.

    • Check earthing line for open circuit and damage.
Repair or replace the connector.