Code No. P2253: Oxygen Sensor Offset Circuit High Voltage




OPERATION




FUNCTION




TROUBLE JUDGMENT


Check Condition
Judgement Criterion
FAIL-SAFE AND BACKUP FUNCTION

PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. Check oxygen sensor (front) itself.



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

Q. Is the check result normal?

Go to Step 2.
Repair or replace the connector, or replace the oxygen sensor (front).

STEP 2. Check oxygen sensor (rear) itself.



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

Q. Is the check result normal?

Go to Step 3.
Repair or replace the connector, or replace the oxygen sensor (rear).

STEP 3. Perform voltage measurement at engine-ECU connector.



  • Disconnect engine-ECU connector, and connect special tool power plant ECU check harness (MB992110) to measure at connector for inspection.
  • Ignition switch: "ON"
  • Voltage between terminal OFLE and body earth.
OK: 0.4 - 0.6 V

Q. Is the check result normal?

Go to Step 7.
Go to Step 4.

STEP 4. Check harness between oxygen sensor (front) connector terminal and engine-ECU connector terminal OFLE.



  • Check earthing line for short circuit.

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 oxygen sensor (front) connector terminal and engine-ECU connector terminal O2FL.



  • Check output line for short circuit.

Q. Is the check result normal?

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

STEP 6. M.U.T.-III diagnosis code



  • Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?

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

STEP 7. Perform voltage measurement at engine-ECU connector.



  • Disconnect engine-ECU connector, and connect special tool power plant ECU check harness (MB992110) to measure at connector for inspection.
  • Ignition switch: "ON"
  • Voltage between terminal ORLE and body earth.
OK: 0.4 - 0.6 V

Q. Is the check result normal?

Go to Step 6.
Go to Step 8.

STEP 8. Check harness between oxygen sensor (rear) connector terminal and engine-ECU connector terminal ORLE.



  • Check earthing line for short circuit.

Q. Is the check result normal?

Go to Step 9.
Repair or replace the connector, or repair the damaged harness wire.

STEP 9. Check harness between oxygen sensor (rear) connector terminal and engine-ECU connector terminal O2RL.



  • Check output line for short circuit.

Q. Is the check result normal?

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