Inspection Procedure 23: Alternator System








OPERATION



  • The excitation current is supplied from the engine-ECU (terminal No. 110) to the alternator (terminal No. 1).
  • The alternator load signal is inputted from the alternator (terminal No. 2) to the engine-ECU (terminal No. 107).

FUNCTION



  • Controls the initiating excitation current to the alternator in accordance with the signals provided by the engine-ECU.

PROBABLE CAUSES



  • Failed alternator
  • Open/short circuit or harness damage in alternator circuit or loose connector contact
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-13 alternator connector

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

STEP 2. Perform voltage measurement at B-13 alternator connector.

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

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

    Check and repair harness between battery and B-13 (terminal No. 1) alternator connector.

    • Check power supply line for open/short circuit.

STEP 3. Check harness between battery and B-13 (terminal No. 1) alternator connector.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 4 .
Repair the damaged harness wire.

STEP 4. Connector check: B-14 alternator connector

Q. Is the check result normal?
Go to Step 5 .
Repair or replace the connector.

STEP 5. Connector check: B-16 engine-ECU connector

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

STEP 6. Check harness between B-14 alternator connector and B-16 (terminal No. 107) engine-ECU connector.

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

Q. Is the check result normal?
Go to Step 7 .
Repair the damaged harness wire.

STEP 7. Check harness between B-14 alternator connector and B-16 (terminal No. 110) engine-ECU connector.

  • 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. Replace the alternator.

  • After replacing the alternator, re-check the trouble symptoms.

Q. Does trouble symptom persist?
Replace the engine-ECU.
The check is end.