Code No. P0620: Alternator Control Circuit




OPERATION




FUNCTION




TROUBLE JUDGEMENT


Check Conditions
Judgement Criterion
Check Conditions
Judgement Criterion

FAIL-SAFE AND BACKUP FUNCTION




PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. Checking engine start conditions



  • Check whether the user uses the booster cable to start the engine.
note This diagnosis code can be output due to the battery voltage drop.

Q. Have you ever used the booster cable to start the engine?

Delete the diagnosis code and check end.
Go to Step 2.

STEP 2. Battery check



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

Q. Is the check result normal?

Go to Step 3.
Replace the battery.

STEP 3. Drive belt tension check



  • Drive belt tension check (Refer to GROUP 11C - On-vehicle Service - Drive Belt Tension Check )

Q. Is the check result normal?

Go to Step 4.
Replace the drive belt.

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



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

Q. Is the check result normal?

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

STEP 5. Check harness between alternator connector terminal and engine-ECU connector terminal ALTL.



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

Q. Is the check result normal?

Go to Step 6.
Repair or replace the connector, or repair the damaged harness wire.

STEP 6. Check harness between battery and engine-ECU connector terminal BACK.



  • Check power supply line for damage.

Q. Is the check result normal?

Go to Step 7.
Repair or replace the connector, or repair the damaged harness wire.

STEP 7. M.U.T.-III diagnosis code



  • Reconfirmation of diagnosis code.

Q. Is diagnosis code stored?

Go to Step 8.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 8. Replace the drive belt



  • After replacing the drive belt, reconfirm whether the diagnosis code is stored.

Q. Is diagnosis code stored?

Go to Step 9.
Check end.

STEP 9. Replace the alternator



  • After replacing the alternator, reconfirm whether the diagnosis code is stored.

Q. Is diagnosis code stored?

Replace the engine-ECU.
Check end.