Code No. P1276 : Fuel Filter Exchange <Vehicles with fuel filter pressure switch>




OPERATION



FUNCTION



TROUBLE JUDGMENT


Check Condition
Judgment Criterion

PROBABLE CAUSES




DIAGNOSIS PROCEDURE

STEP 1. Connector check: A-143 fuel filter pressure switch connector.

Q. Is the check result normal?

Go to Step 2 .

Repair or replace the connector.

STEP 2. Check fuel filter pressure switch itself

  • Check the fuel filter pressure switch itself (Refer to GROUP 13B - Fuel Filter and Glow Plug Relay - Fuel Filter Inspection ).

Q. Is the check result normal?
Replace the fuel filter body.
Go to Step 3 .

STEP 3. Perform voltage measurement at A-143 fuel filter pressure switch connector.


  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 1 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 7 .

Go to Step 4 .

STEP 4. Connector check: C-103 engine-ECU connector.

Q. Is the check result normal?

Go to Step 5 .

Repair or replace the connector.

STEP 5. Check harness between C-103 (terminal No. 102) engine-ECU connector and A-143 (terminal No. 1) fuel filter pressure switch connector.



  • Check output line for open/short circuit.

Q. Is the check result normal?

Go to Step 6 .

Repair the damaged harness wire.

STEP 6. M.U.T.-III data list

  • Refer to Data List Reference Table .

    1. Item 152: Fuel filter pressure switch

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

STEP 7. Perform resistance measurement at A-143 fuel filter pressure switch connector.


  • Disconnect connector, and measure at harness side.
  • Resistance between terminal No. 2 and earth.
OK: Continuity (2 Ω or less)

Q. Is the check result normal?

Go to Step 8 .


    Check and repair harness between B-143 (terminal No. 2) fuel filter pressure switch connector and body earth.

    • Check earthing line for open circuit and damage.

STEP 8: Connector check: C-103 engine-ECU connector

Q. Is the check result normal?

Go to Step 9 .

Repair or replace the connector.

STEP 9: Check harness between C-103 (terminal No. 102) engine-ECU connector and A-143 (terminal No. 1) fuel filter pressure switch connector.



  • Check output line for damage.

Q. Is the check result normal?

Replace the fuel filter.

Repair the damaged harness wire.