P2252

DTC P2252: Heated Oxygen Sensor Offset Circuit Low Voltage






















HEATED OXYGEN SENSOR OFFSET CIRCUIT LOW VOLTAGE CIRCUIT

Refer to DTC P0131 - Heated Oxygen Sensor Circuit Low Voltage (bank 1, sensor 1) P0131.
Refer to DTC P0137 - Heated Oxygen Sensor Circuit Low Voltage (bank 1, sensor 2) P0137.
Refer to DTC P0151 - Heated Oxygen Sensor Circuit Low Voltage (bank 2, sensor 1) P0151.
Refer to DTC P0157 - Heated Oxygen Sensor Circuit Low Voltage (bank 2, sensor 2) P0157.

CIRCUIT OPERATION

Refer to DTC P0131 - Heated Oxygen Sensor Circuit Low Voltage (bank 1, sensor 1) P0131.
Refer to DTC P0137 - Heated Oxygen Sensor Circuit Low Voltage (bank 1, sensor 2) P0137.
Refer to DTC P0151 - Heated Oxygen Sensor Circuit Low Voltage (bank 2, sensor 1) P0151.
Refer to DTC P0157 - Heated Oxygen Sensor Circuit Low Voltage (bank 2, sensor 2) P0157.

TECHNICAL DESCRIPTION

- The ECM applies an offset voltage of 0.5 volt to the heated oxygen sensor.

- The ECM checks for heated oxygen sensor offset voltage.

DESCRIPTIONS OF MONITOR METHODS

Heated oxygen sensor offset voltage is under specified range.

MONITOR EXECUTION

Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)

- Not applicable
Sensor (The sensor below is determined to be normal)

- Not applicable

DTC SET CONDITION

Logic Flow Chart





Check Condition

- 2 seconds or more have passed since the engine starting sequence was completed.
Judgement Criterion

- Heated oxygen sensor offset voltage is lower than 0.4 volt for 2 seconds.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnosis Function - OBD-II Drive Cycle - Pattern 22 Monitors, Trips, Drive Cycles and Readiness Codes.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)

- Right bank heated oxygen sensor (front) failed.

- Right bank heated oxygen sensor (rear) failed.

- Left bank heated oxygen sensor (front) failed.

- Left bank heated oxygen sensor (rear) failed.

- Shorted right bank heated oxygen sensor (front) circuit or connector damage.

- Shorted right bank heated oxygen sensor (rear) circuit or connector damage.

- Shorted left bank heated oxygen sensor (front) circuit or connector damage.

- Shorted left bank heated oxygen sensor (rear) circuit or connector damage.

- ECM failed.

DIAGNOSIS

Required Special Tools:

- MB991958: Scan tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.

- MB991827: USB Cable

- MB991910: Main Harness A

- MB991316: Test Harness

- MD998464: Test Harness

STEP 1. Check harness connector B-03 at right bank heated oxygen sensor (front), harness connector B-02 at right bank heated oxygen sensor (rear), harness connector B-14 at left bank heated oxygen sensor (front), harness connector B-13 at left bank heated oxygen sensor (rear) and harness connector B-10 at ECM for damage.

Q. Are the harness connectors in good condition?

YES Go to Step 2.
NO Repair or replace them. Harness Connector Inspection.
Then go to Step 11.
STEP 2. Check the right bank heated oxygen sensor (front).

(1)Disconnect the right bank heated oxygen sensor (front) connector B-03 and connect test harness special tool MB991316 to the connector on the right bank heated oxygen sensor (front) side.

(2)Warm up the engine until engine coolant temperature reaches 80°C (176°F) or higher.

(3)Rev the engine for 5 minutes or more with the engine speed of 2,000 r/min.





(4)Connect a digital voltage meter between terminal No. 2 (black clip) and terminal No. 4
(white clip).
(5)While repeatedly revving the engine, measure the right bank heated oxygen sensor
(front) output voltage.
Standard value: 0.6 - 1.0 V

CAUTION:

- Be very careful when connecting the jumper wires; incorrect connection can damage the heated oxygen sensor.

- Be careful the heater can be damaged if a voltage beyond 8 volts is applied to the heated oxygen sensor heater.

NOTE:
If the temperature of sensing area does not reach the high temperature [of approximately 400°C (752°F) or more] even though the heated oxygen sensor is normal, the output voltage would be possibly low in spite of the rich air/ fuel ratio. Therefore, if the output voltage is low, use a jumper wire to connect the terminal No. 1 (red clip) and the terminal No. 3 (blue clip) of the heated oxygen sensor with the positive terminal and the negative terminal of 8 volts power supply respectively, then check again.

Q. Is the measured voltage between 0.6 and 1.0 volt?

YES Go to Step 3.

NO Replace the right bank heated oxygen sensor (front). Then go to Step 11.

STEP 3. Check the left bank heated oxygen sensor (front).

(1)Disconnect the left bank heated oxygen sensor (front) connector B-14 and connect test harness special tool MD998464 to the connector on the left bank heated oxygen sensor (front) side.

(2)Warm up the engine until engine coolant temperature reaches 80°C (176°F) or higher.

(3)Rev the engine for 5 minutes or more with the engine speed of 2,000 r/min.





(4)Connect a digital voltage meter between terminal No. 2 (black clip) and terminal No. 4
(white clip).
(5)While repeatedly revving the engine, measure the left bank heated oxygen sensor
(front) output voltage.
Standard value: 0.6 - 1.0 V

CAUTION:

- Be very careful when connecting the jumper wires; incorrect connection can damage the heated oxygen sensor.

- Be careful the heater can be damaged if a voltage beyond 8 volts is applied to the heated oxygen sensor heater.

NOTE:
If the temperature of sensing area does not reach the high temperature [of approximately 400°C (752°F) or more] even though the heated oxygen sensor is normal, the output voltage would be possibly low in spite of the rich air/ fuel ratio. Therefore, if the output voltage is low, use a jumper wire to connect the terminal No. 1 (red clip) and the terminal No. 3 (blue clip) of the heated oxygen sensor with the positive terminal and the negative terminal of 8 volts power supply respectively, then check again.

Q. Is the measured voltage between 0.6 and 1.0 volt?

YES Go to Step 4.

NO Replace the left bank heated oxygen sensor (front). Then go to Step 11.

STEP 4. Check the right bank heated oxygen sensor (rear).

(1)Disconnect the right bank heated oxygen sensor (rear) connector B-02 and connect test harness special tool MD998464 to the connector on the right bank heated oxygen sensor (rear) side.

(2)Warm up the engine until engine coolant temperature reaches 80°C (176°F) or higher.

(3)Drive at 50 km/h (31 mph) or more for 10 minutes.





(4)Connect a digital voltage meter between terminal No. 2 (black clip) and terminal No. 4
(white clip).
(5)Measure the output voltage of heated oxygen sensor under the following driving.

- Transaxle: 2nd speed

- Drive with wide open throttle

- Engine: 3,500 r/min or more
Standard value: 0.6 - 1.0 V
NOTE:
If the temperature of sensing area does not reach the high temperature [of approximately 400°C (752°F) or more] even though the heated oxygen sensor is normal, the output voltage would be possibly low in spite of the rich air-fuel ratio.

NOTE:
When the vehicle is driven with high loads, the temperature of the sensing area of the heated oxygen sensor is sufficiently high. Thus, it is not necessary to apply the voltage to the heater.

Q. Is the measured voltage between 0.6 and 1.0 volt?

YES Go to Step 5.

NO Replace the right bank heated oxygen sensor (rear). Then go to Step 11.

STEP 5. Check the left bank heated oxygen sensor (rear).

(1)Disconnect the left bank heated oxygen sensor (rear) connector B-13 and connect test harness special tool MB991316 to the connector on the left bank heated oxygen sensor (rear) side.

(2)Warm up the engine until engine coolant temperature reaches 80°C (176°F) or higher.

(3)Drive at 50 km/h (31 mph) or more for 10 minutes.





(4)Connect a digital voltage meter between terminal No. 2 (black clip) and terminal No. 4
(white clip).
(5)Measure the output voltage of heated oxygen sensor under the following driving.

- Transaxle: 2nd speed

- Drive with wide open throttle

- Engine: 3,500 r/min or more
Standard value: 0.6 - 1.0 V
NOTE:
If the temperature of sensing area does not reach the high temperature [of approximately 400°C (752°F) or more] even though the heated oxygen sensor is normal, the output voltage would be possibly low in spite of the rich air-fuel ratio.

NOTE:
When the vehicle is driven with high loads, the temperature of the sensing area of the heated oxygen sensor is sufficiently high. Thus, it is not necessary to apply the voltage to the heater.

Q. Is the measured voltage between 0.6 and 1.0 volt?

YES Go to Step 6.

NO Replace the left bank heated oxygen sensor (rear). Then go to Step 11.

STEP 6. Check for short circuit to ground between the right bank heated oxygen sensor (front) connector B-03 and the ECM connector B-10.





(1)Disconnect the right bank heated oxygen sensor (front) connector B-03 and the ECM connector B-10.
(2)Check for the continuity between the right bank heated oxygen sensor (front) connector B-03 (terminal No. 2) and ground.

- Not continuity.

Q. Is the harness wire in good condition?

YES Go to Step 7.

NO Repair it. Harness Connector Inspection.
Then go to Step 11.

STEP 7. Check for short circuit to ground between the left bank heated oxygen sensor (front) connector B-14 and the ECM connector B-10.





(1)Disconnect the left bank heated oxygen sensor (front) connector B-14 and the ECM connector B-10.
(2)Check for the continuity between the left bank heated oxygen sensor (front) connector B-14 (terminal No. 2) and ground.

- Not continuity.

Q. Is the harness wire in good condition?

YES Go to Step 8.

NO Repair it. Harness Connector Inspection.
Then go to Step 11.

STEP 8. Check for short circuit to ground between the right bank heated oxygen sensor (rear) connector B-02 and the ECM connector B-10.





(1)Disconnect the right bank heated oxygen sensor (rear) connector B-02 and the ECM connector B-10.
(2)Check for the continuity between the right bank heated oxygen sensor (rear) connector B-02 (terminal No. 2) and ground.

- Not continuity.

Q. Is the harness wire in good condition?

YES Go to Step 9 .

NO Repair it. Harness Connector Inspection.
Then go to Step 11.

STEP 9. Check for short circuit to ground between the left bank heated oxygen sensor (rear) connector B-13 and the ECM connector B-10.





(1)Disconnect the left bank heated oxygen sensor (rear) connector B-13 and the ECM connector B-10.
(2)Check for the continuity between the left bank heated oxygen sensor (rear) connector B-13 (terminal No. 2) and ground.

- Not continuity.

Q. Is the harness wire in good condition?

YES Go to Step 10 .

NO Repair it. Harness Connector Inspection.
Then go to Step 11.

STEP 10. Check the trouble symptoms.

(1)Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle Pattern 22 Monitors, Trips, Drive Cycles and Readiness Codes.

(2)Check the diagnostic trouble code (DTC).

Q. Is DTC P2252 set?

YES Replace the ECM. When the ECM is replaced, register the ID code. Refer to ID registration procedure manual - ID codes registration judgement table [Vehicles with KOS] or ID registration procedure manual - ID codes registration judgement table [Vehicles with WCM]. Then go to Step 11.
NO It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
STEP 11. Test the OBD-II drive cycle.

(1)Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle Pattern 22 Monitors, Trips, Drive Cycles and Readiness Codes.

(2)Check the diagnostic trouble code (DTC).

Q. Is DTC P2252 set?

YES Retry the troubleshooting.
NO The inspection is complete.