Code No. P2252: Oxygen Sensor Offset Circuit Low Voltage

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 less than 0.4 V for 2 seconds.

FAIL-SAFE AND BACKUP FUNCTION

None

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. 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.

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 oxygen sensor (front) 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 engine-ECU OFLE line and body earth.

OK: 0.4 - 0.6 V

Q. Is the check result normal?

	Go to Step 6.

	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. 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 6. Perform voltage measurement at oxygen sensor (rear) 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 engine-ECU ORLE and body earth.

OK: 0.4 - 0.6 V

Q. Is the check result normal?

	Go to Step 5.

	Go to Step 7.

STEP 7. 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 5.

	Repair or replace the connector, or repair the damaged harness wire.