Code No. P0622: Alternator FR Terminal System <Vehicles with battery current sensor>








OPERATION



  • The energised state of the alternator field coil is inputted from the alternator (terminal No. 4) to the engine-ECU (terminal No. 141).

FUNCTION



  • A signal of the power supply duty ratio for the alternator field coil is inputted to the engine-ECU.
  • In response to the signal, the engine-ECU detects the alternator output current and controls the idling speed according to the output current (electric load).

TROUBLE JUDGMENT


Check Condition
  • Engine is running.
Judgement Criterion
  • Input voltage from the alternator FR terminal is battery positive voltage for 20 seconds.

PROBABLE CAUSES



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

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-116 alternator connector

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

STEP 2. Perform voltage measurement at B-116 alternator connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 4 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 6.
Go to Step 3.

STEP 3. Connector check: D-215 engine-ECU connector

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

STEP 4. Check harness between B-116 (terminal No. 4) alternator connector and D-215 (terminal No. 141) engine-ECU connector.
note Before checking harness, check intermediate connector B-46, and repair if necessary.

  • Check output line for open circuit.

Q. Is the check result normal?
Go to Step 5.
Repair the damaged harness wire.

STEP 5. M.U.T.-III diagnosis code

  • Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?
Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - Precautions Before Service - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ). After registering the injector identification code, the vehicle equipped with the closed type DPF carries out the forcible DPF regeneration. (Refer to GROUP 17 - Diesel Particulate Filter (DPF) System - Forcible DPF Regeneration ).
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 6. Connector check: D-215 engine-ECU connector

Q. Is the check result normal?
Go to Step 7.
Repair or replace the connector.

STEP 7. Check harness between B-116 (terminal No. 4) alternator connector and D-215 (terminal No. 141) engine-ECU connector.
note Before checking harness, check intermediate connector B-46, and repair if necessary.

  • Check output line for damage.

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

STEP 8. Perform voltage measurement at D-215 engine-ECU connector.

  • Measure engine-ECU terminal voltage.
  • Engine: Idle operation after warm-up
  • Transmission: Neutral <M/T> or P range <A/T>
  • Voltage between terminal No. 141 and earth.
OK: The voltage decreases when the headlamp switch and the rear window defogger switch are turned ON from OFF.

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