Code No. P0622: Alternator FR Terminal System








OPERATION



  • The energised state of the alternator field coil is inputted from the alternator (terminal No. 4) to the engine-ECU <M/T> or engine-A/T-ECU <A/T> (terminal No. 86).

FUNCTION



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

TROUBLE JUDGMENT


Check Condition
  • Engine speed is 500 r/min or higher.
Judgment Criterion
  • Input voltage from the alternator FR terminal has continued to be approximately battery positive voltage for 20 seconds.

PROBABLE CAUSES



  • Failed alternator
  • Open circuit in alternator FR terminal circuit or loose connector contact
  • Failed engine-ECU <M/T> or engine-A/T-ECU <A/T>

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-245 engine-ECU <M/T> connector or D-216 engine-A/T-ECU <A/T> 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-245 (terminal no. 86) engine-ECU <M/T> connector or D-216 (terminal No. 86) engine-A/T-ECU <A/T> connector.
note Before checking harness, check intermediate connector B-20, 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. Check the trouble symptoms.

Q. Does trouble symptom persist?
Replace the engine-ECU <M/T> or engine-A/T-ECU <A/T>.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 6. Perform voltage measurement at D-245 engine-ECU <M/T> connector or D-216 engine-A/T-ECU <A/T> connector.

  • Measure engine-ECU <M/T> or engine-A/T-ECU <A/T> terminal voltage.
  • Engine: Idle after warm-up
  • Transmission: Neutral <M/T> or P range <A/T>
  • Radiator fan: Inactive
  • Voltage between terminal No. 86 and earth.
OK: Switching the headlamps to ON from OFF causes the voltage to fall.

Q. Is the check result normal?
Go to Step 5.
Go to Step 7.

STEP 7. Connector check: D-245 engine-ECU <M/T> connector or D-216 engine-A/T-ECU <A/T> connector.

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

STEP 8. Check harness between B-116 (terminal No. 4) alternator connector and D-245 (terminal no. 86) engine-ECU <M/T> connector or D-216 (terminal No. 86) engine-A/T-ECU <A/T> connector.
note Before checking harness, check intermediate connector B-20, and repair if necessary.

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 9.
Repair the damaged harness wire.

STEP 9. Check trouble symptom.

Q. Same symptoms regenerated?
Replace the alternator.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).