Code No. P0622: Alternator FR Terminal System




OPERATION




FUNCTION




TROUBLE JUDGEMENT


Check Condition
Judgement Criterion

FAIL-SAFE AND BACKUP FUNCTION




PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. Perform voltage measurement at alternator connector.



  • Disconnect connector, and measure at harness side.
  • Ignition switch: "ON"
  • Voltage between terminal engine-ECU ALTF line and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 4.
Go to Step 2.

STEP 2. Check harness between alternator connector terminal and engine-ECU connector terminal ALTF.



  • Check output line for open circuit.

Q. Is the check result normal?

Go to Step 3.
Repair or replace the connector, or repair the damaged harness wire.

STEP 3. M.U.T.-III diagnosis code



  • Reconfirmation of diagnosis code.

Q. Is diagnosis code stored?

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

STEP 4. Check harness between alternator connector terminal and engine-ECU connector terminal ALTF.



  • Check output line for damage.

Q. Is the check result normal?

Go to Step 5.
Repair or replace the connector, or repair the damaged harness wire.

STEP 5. Perform voltage measurement at engine-ECU connector.



  • Disconnect engine-ECU connector, and connect special tool power plant ECU check harness (MB992110) to measure at connector for inspection.
  • Engine: Idle operation after warm-up
  • Transmission: Neutral <M/T> or P range <CVT>
  • Radiator fan: Not operated
  • Voltage between terminal ALTF and body earth.
OK: Voltage decreases when the headlamps are extinguished → illuminated.

Q. Is the check result normal?

Go to Step 3.
Replace the alternator.