Code No. P0134: Oxygen Sensor (front) Circuit No Activity Detected




OPERATION




FUNCTION




TROUBLE JUDGMENT


Check Conditions
Judgement Criterion

FAIL-SAFE AND BACKUP FUNCTION




PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III data list



  • Data list reference table (Refer to ).

  1. Item AC: Oxygen sensor (front)

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 ).
Go to Step 2.

STEP 2. Check for exhaust leaks.


Q. Is the check result normal?

Go to Step 3.
Repair.

STEP 3. Check for intake system vacuum leak.


Q. Is the check result normal?

Go to Step 4.
Repair.

STEP 4. Check oxygen sensor (front) itself.



  • Oxygen sensor (front) connector check.
  • Oxygen sensor (front) check (Refer to ).

Q. Is the check result normal?

Go to Step 5.
Repair or replace the connector, or replace the oxygen sensor (front).

STEP 5. Check injector itself.



  • No.1, No.2, No.3, No.4 injector connector check.
  • Injector check (Refer to ).

Q. Is the check result normal?

Go to Step 6.
Repair or replace the connector, or replace the injector.

STEP 6. Check harness between oxygen sensor (front) connector terminal and engine-ECU connector terminal O2FL.



  • Check output 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. Check harness between injector connector and engine-ECU connector.



  1. Check and repair harness between No. 1 injector connector terminal and engine-ECU connector terminal INJ1.
  2. Check and repair harness between No. 2 injector connector terminal and engine-ECU connector terminal INJ2.
  3. Check and repair harness between No. 3 injector connector terminal and engine-ECU connector terminal INJ3.
  4. Check and repair harness between No. 4 injector connector terminal and engine-ECU connector terminal INJ4.

  • Check output line for damage.

Q. Are the check result normal?

Go to Step 8.
Repair or replace the connector, or repair the damaged harness wire.

STEP 8. Fuel pressure measurement.



  • Fuel pressure test (Refer to ).

Q. Is the check result normal?

Replace the engine-ECU.
Repair.