Code No. P2253: Oxygen Sensor Offset Circuit High Voltage <Except vehicles for Russia>


OPERATION



  • Check code No. P0131: oxygen sensor (front) circuit low voltage (Refer to ).
  • Check code No. P0137: oxygen sensor (rear) circuit low voltage (Refer to ).

FUNCTION



  • The engine-ECU watches and checks whether the offset voltage of the oxygen sensor is normal or not.

TROUBLE JUDGMENT


Check Condition
  • More than 2 seconds have passed since the engine starting sequence was completed.
Judgement Criterion
  • Oxygen sensor offset voltage is more than 0.6 V for 2 seconds.
FAIL-SAFE AND BACKUP FUNCTION
  • Does not control air-fuel ratio closed loop.

PROBABLE CAUSES



  • Failed oxygen sensor (front)
  • Failed oxygen sensor (rear)
  • Short circuit in oxygen sensor (front) circuit or loose connector contact
  • Short circuit in oxygen sensor (rear) circuit or loose connector contact
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-32 oxygen sensor (front) connector and C-36 oxygen sensor (rear) connector

Q. Are the check results normal?
Go to Step 2.
Repair or replace the connector.

STEP 2. Check oxygen sensor (front) itself.

  • Oxygen sensor check (Refer to ).

Q. Is the check result normal?
Go to Step 3.
Replace the oxygen sensor (front).

STEP 3. Check oxygen sensor (rear) itself.

  • Oxygen sensor check (Refer to ).

Q. Is the check result normal?
Go to Step 4.
Replace the oxygen sensor (rear).

STEP 4. Connector check: B-26 engine-ECU connector

Q. Is the check result normal?
Go to Step 5.
Repair or replace the connector.

STEP 5. Perform voltage measurement at B-26 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 No. 39 and earth.
OK: 0.4 - 0.6 V

Q. Is the check result normal?
Go to Step 9.
Go to Step 6.

STEP 6. Check harness between B-32 (terminal No. 2) oxygen sensor (front) connector and B-26 (terminal No. 39) engine-ECU connector.

  • Check earthing line for short circuit.

Q. Is the check result normal?
Go to Step 7.
Repair the damaged harness wire.

STEP 7. Check harness between B-32 (terminal No. 1) oxygen sensor (front) connector and B-26 (terminal No. 38) engine-ECU connector.

  • Check output line for short circuit.

Q. Is the check result normal?
Go to Step 8.
Repair the damaged harness wire.

STEP 8. 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 9. Perform voltage measurement at B-26 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 No. 41 and earth.
OK: 0.4 - 0.6 V

Q. Is the check result normal?
Go to Step 8.
Go to Step 10.

STEP 10. Check harness between C-36 (terminal No. 4) oxygen sensor (rear) connector and B-26 (terminal No. 41) engine-ECU connector.
note Before checking harness, check intermediate connector A-17, and repair if necessary.

  • Check earthing line for short circuit.

Q. Is the check result normal?
Go to Step 11.
Repair the damaged harness wire.

STEP 11. Check harness between C-36 (terminal No. 3) oxygen sensor (rear) connector and B-26 (terminal No. 40) engine-ECU connector.
note Before checking harness, check intermediate connector A-17, and repair if necessary.

  • Check output line for short circuit.

Q. Is the check result normal?
Go to Step 8.
Repair the damaged harness wire.