Inspection Procedure 4: Starting Impossible (starter not operative)


OPERATION



  • The power source is supplied from the battery to the starter (B-113 terminal No. 1).
  • The battery voltage is applied to the starter relay (terminal No. 4).
  • When the ignition switch-ST signal is input to the engine-ECU (terminal No. 105), the engine-ECU (terminal No. 106) turns ON the power transistor inside the unit, and makes the current flow into the starter relay (terminal No. 2) to turn ON the relay.
  • When the starter relay is turned ON, the current flows into the starter (B-112 terminal No. 1) from the starter relay (terminal No. 3) to drive the starter motor.

COMMENTS ON TROUBLE SYMPTOM



  • The failure could possibly be caused by the malfunction of the starter or starter system circuits.

PROBABLE CAUSES



  • Failed battery
  • Failed ignition switch <Vehicles without KOS>
  • Failed OSS-ECU <Vehicles with KOS>
  • Failed starter relay
  • Failed starter motor
  • Open/short circuit or harness damage in starter system circuit or loose connector contact.
  • Failed ETACS-ECU
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check battery.

  • Check battery (Refer to GROUP 54A - Battery - On-vehicle Service - Battery Test ).

Q. Is the check result normal?
Go to Step 2 .
Replace the battery.

STEP 2. M.U.T.-III data list

  • Item 79: Cranking signal
OK:
    ON (ignition switch: ST)
    OFF (ignition switch: ON)

Q. Is the check result normal?
Go to Step 19 .
Go to Step 3 .

STEP 3. Connector check: B-27 engine-ECU connector

Q. Is the check result normal?
Go to Step 4 .
Repair or replace the connector.

STEP 4. Perform voltage measurement at B-27 engine-ECU connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ST
  • Voltage between terminal No. 105 and earth.
OK: System voltage

Q. Is the check result normal?
YES : Go to Step 12 <Vehicles without KOS> .
YES : Go to Step 14 <Vehicles with KOS> .
Go to Step 5 .

STEP 5. Connector check: C-403 and C-415 ETACS-ECU connectors

Q. Are the check results normal?
Go to Step 6 .
Repair or replace the connector.

STEP 6. Perform voltage measurement at C-415 ETACS-ECU connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ST
  • Voltage between terminal No. 7 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 11 .
NO : Go to Step 7 <Vehicles without KOS> .
NO : Go to Step 9 <Vehicles with KOS> .

STEP 7. Connector check: C-309 ignition switch connector

Q. Is the check result normal?
Go to Step 8 .
Repair or replace the connector.

STEP 8. 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 the harness between C-309 (terminal No. 5) ignition switch connector and C-415 (terminal No. 7) ETACS-ECU connector.

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

STEP 9. Connector check: C-14 OSS-ECU connector

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

STEP 10. Check harness between C-14 (terminal No. 23) OSS-ECU connector and C-415 (terminal No. 7) ETACS-ECU connector.

  • Check power supply line for open/short circuit.

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

STEP 11. Continuity check on C-415 and C-403 ETACS-ECU connectors

  • Disconnect connectors, and measure at ETACS-ECU side.
  • Continuity check between terminal No. 7 (C-415) and No. 15 (C-403)
OK: Continuity

Q. Is the check result normal?

    Check and repair the harness between C-403 (terminal No. 15) ETACS-ECU connector and B-27 (terminal No. 105) engine-ECU connector.

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

STEP 12. Connector check: C-309 ignition switch connector and C-403 and C-415 ETACS-ECU connectors

Q. Are the check results normal?
Go to Step 13 .
Repair or replace the connector.

STEP 13. Check harness between C-309 (terminal No. 5) ignition switch connector and C-415 (terminal No. 7) ETACS-ECU connector.

  • Check power supply line for damage.

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

STEP 14. Connector check: C-14 OSS-ECU connector and C-403 and C-415 ETACS-ECU connectors

Q. Are the check results normal?
Go to Step 15 .
Repair or replace the connector.

STEP 15. Check harness between C-14 (terminal No. 23) OSS-ECU connector and C-415 (terminal No. 7) ETACS-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. Continuity check on C-415 and C-403 ETACS-ECU connectors

  • Disconnect connectors, and measure at ETACS-ECU side.
  • Continuity check between terminal No. 7 (C-415) and No. 15 (C-403)
OK: Continuity

Q. Is the check result normal?
Go to Step 17 .
Replace the ETACS-ECU.

STEP 17. Check harness between C-403 (terminal No. 15) ETACS-ECU connector and B-27 (terminal No. 105) engine-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. M.U.T.-III data list

  • Item 79: Cranking signal
OK:
    ON (ignition switch: ST)
    OFF (ignition switch: ON)

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

STEP 19. Connector check: A-31X starter relay connector

Q. Is the check result normal?
Go to Step 20 .
Repair or replace the connector.

STEP 20. Check starter relay itself.

  • Check starter relay itself (Refer to GROUP 16 - Starting System - On-vehicle Service - Starter Relay Continuity Check ).

Q. Is the check result normal?
Go to Step 21 .
Replace the starter relay.

STEP 21. Perform resistance measurement at A-31X starter relay connector.

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

Q. Is the check result normal?
Go to Step 22 .

    Check and repair harness between A-31X (terminal No. 1) starter relay connector and body earth.

    • Check earthing line for open circuit and damage.

STEP 22. Perform voltage measurement at A-31X starter relay connector.

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

Q. Is the check result normal?
Go to Step 33 .
NO : Go to Step 23 <Vehicles without KOS> .
NO : Go to Step 25 <Vehicles with KOS> .

STEP 23. Connector check: B-27 engine-ECU connector

Q. Is the check result normal?
Go to Step 24 .
Repair or replace the connector.

STEP 24. Check harness between B-27 (terminal No. 106) engine-ECU connector and A-31X (terminal No. 2) starter relay connector.
note Before checking harness, check intermediate connector C-236, and repair if necessary.

  • Check power supply line for open/short circuit.

Q. Is the check result normal?
Go to Step 30 .
Repair the damaged harness wire.

STEP 25. Connector check: C-230 clutch interlock switch connector

Q. Is the check result normal?
Go to Step 26 .
Repair or replace the connector.

STEP 26. Check clutch interlock switch.

  • Check clutch interlock switch (Refer to GROUP 21A - Clutch Pedal and Master Cylinder - Inspection ).

Q. Is the check result normal?
Go to Step 27 .
Replace the clutch interlock switch.

STEP 27. Check harness between C-230 (terminal No. 2) interlock switch connector and A-31X (terminal No. 2) starter relay connector.

  • Check power supply line for open/short circuit.

Q. Is the check result normal?
Go to Step 28 .
Repair the damaged harness wire.

STEP 28. Connector check: B-27 engine-ECU connector

Q. Is the check result normal?
Go to Step 29 .
Repair or replace the connector.

STEP 29. Check harness between B-27 (terminal No. 106) engine-ECU connector and C-230 (terminal No. 1) clutch interlock switch connector.

  • Check power supply line for open/short circuit.

Q. Is the check result normal?
Go to Step 30 .
Repair the damaged harness wire.

STEP 30. Connector check: B-26 engine-ECU connector

Q. Is the check result normal?
Go to Step 31 .
Repair or replace the connector.

STEP 31. Check harness between B-26 (terminal No. 6) engine-ECU connector and A-31X (terminal No. 2) starter relay connector.
note Before checking harness, check intermediate connector A-17, and repair if necessary.

  • Check output line for short circuit.

Q. Is the check result normal?
Go to Step 32 .
Repair the damaged harness wire.

STEP 32. M.U.T.-III data list

  • Item 102: Starter relay
OK:
    ON (ignition switch: ST)
    OFF (ignition switch: ON)

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

STEP 33. Perform voltage measurement at A-31X starter relay connector.

  • Remove relay, and measure at relay box side.
  • Voltage between terminal No. 4 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 34 .

    Check and repair harness between battery and A-31X (terminal No. 4) starter relay connector.

    • Check power supply line for open/short circuit.

STEP 34. Connector check: B-112 starter connector

Q. Is the check result normal?
Go to Step 35 .
Repair or replace the connector.

STEP 35. Perform voltage measurement at B-112 starter connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ST
  • Voltage between terminal No. 1 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 42 .
Go to Step 36 .

STEP 36. Check harness between A-31X (terminal No. 3) starter relay connector and B-112 (terminal No. 1) starter connector.
note Before checking harness, check intermediate connector A-17, and repair if necessary.

  • Check output line for open/short circuit.

Q. Is the check result normal?
YES : Go to Step 37 <Vehicles without OSS> .
YES : Go to Step 38 <Vehicles with OSS> .
Repair the damaged harness wire.

STEP 37. Connector check: B-27 engine-ECU connector

Q. Is the check result normal?

    Check intermediate connector C-236, and repair if necessary. If intermediate connector is normal, check and repair harness between B-27 (terminal No. 106) engine-ECU connector and A-31X (terminal No. 2) starter relay connector.

    • Check power supply line for damage.
Repair or replace the connector.

STEP 38. Connector check: C-230 clutch interlock switch

Q. Is the check result normal?
Go to Step 39 .
Repair or replace the connector.

STEP 39. Check clutch interlock switch.

  • Check clutch interlock switch (Refer to GROUP 21A - Clutch Pedal and Master Cylinder - Inspection ).

Q. Is the check result normal?
Go to Step 40 .
Replace the clutch interlock switch.

STEP 40. Check harness between C-230 (terminal No. 2) clutch interlock switch connector and A-31X (terminal No. 2) starter relay connector.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 41 .
Repair the damaged harness wire.

STEP 41. Connector check: B-27 engine-ECU connector

Q. Is the check result normal?

    Check and repair harness between B-27 (terminal No. 106) engine-ECU connector and C-230 (terminal No. 1) clutch interlock switch connector.

    • Check power supply line for damage.
Repair or replace the connector.

STEP 42. Check harness between battery and A-31X (terminal No. 4) starter relay connector.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 43 .
Repair the damaged harness wire.

STEP 43. Check harness between A-31X (terminal No. 3) starter relay connector and B-112 (terminal No. 1) starter connector.
note Before checking harness, check intermediate connector A-17, and repair if necessary.

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 44 .
Repair the damaged harness wire.

STEP 44. Connector check: B-113 starter terminal

Q. Is the check result normal?
Go to Step 45 .
Repair or replace the terminal.

STEP 45. Perform voltage measurement at B-113 starter terminal.

  • Disconnect terminal, and measure at harness side.
  • Voltage between terminal No. 1 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 46 .

    Check and repair harness between battery and B-113 (terminal No. 1) starter terminal.

    • Check power supply line for open/short circuit.

STEP 46. Check harness between battery and B-113 (terminal No. 1) starter terminal.

  • Check power supply line for damage.

Q. Is the check result normal?
Replace the starter.
Repair the damaged harness wire.