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 ) <EURO4>.

FUNCTION

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

TROUBLE JUDGEMENT

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) <EURO4>
Short circuit in oxygen sensor (front) circuit or loose connector contact
Short circuit in oxygen sensor (rear) circuit or loose connector contact <EURO4>
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check oxygen sensor (front) itself.

Oxygen sensor check (Refer to ).

Q. Is the check result normal?

	YES <EURO4> : Go to Step 2.

	YES <EURO2> : Go to Step 3.

	Replace the oxygen sensor (front).

STEP 2. Check oxygen sensor (rear) itself.

Oxygen sensor check (Refer to ).

Q. Is the check result normal?

	Go to Step 3.

	Replace the oxygen sensor (rear).

STEP 3. Perform voltage measurement at oxygen sensor (front) connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal OFLE line and earth.

OK: 0.4 - 0.6 V

Q. Is the check result normal?

	YES <EURO4> : Go to Step 6.

	YES <EURO2> : Go to Step 5.

	Go to Step 4.

STEP 4. Check of short to earth in OFLE line between oxygen sensor (front) connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 5.

	Repair the connector(s) or wiring harness.

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 connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal ORLE line and earth.

OK: 0.4 - 0.6 V

Q. Is the check result normal?

	Go to Step 5.

	Go to Step 7.

STEP 7. Check of short to earth in ORLE line between oxygen sensor (rear) connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 5.

	Repair the connector(s) or wiring harness.