Code No. P1603: Battery Backup Circuit Malfunction




OPERATION



FUNCTION



TROUBLE JUDGMENT


Check Conditions
Judgment Criterion

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

  • Temporarily place the ignition switch in "LOCK" (OFF) position, and 10 seconds after that, place it in "ON" position again.

Q. Is the diagnosis code P1603 set?
Go to Step 2 .
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 2. Perform voltage measurement at A-09 engine-ECU connector.


  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 82 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 3 .


    Check intermediate connectors B-208 and B-212, and repair if necessary. If intermediate connectors are normal, check and repair harness between battery and A-09 (terminal No. 82) engine-ECU connector.

    • Check power supply line for open/short circuit.

STEP 3. Check harness between battery and A-09 (terminal No. 82) engine-ECU connector.

note Before checking harness, check intermediate connectors B-208 and B-212, and repair if necessary.

  • 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: A-09 engine-ECU connector

Q. Is the check result normal?

Go to Step 5 .

Repair or replace the connector.

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



  • Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?
Replace the engine-ECU then perform the variant coding (Refer to GROUP 00 - Precautions Before Service - How to Perform Variant Coding ).
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).