P0150
DTC P0150: Heated Oxygen Sensor Circuit (bank 2, sensor 1)Left Bank Heated Oxygen Sensor (front) Circuit Part 1:
Left Bank Heated Oxygen Sensor (front) Circuit Part 2:
CIRCUIT OPERATION
- A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the ECM (terminal No. 71)
- Terminal No. 2 of the left bank heated oxygen sensor (front) is grounded with ECM (terminal No. 49)
TECHNICAL DESCRIPTION
- The left bank heated oxygen sensor (front) detects the concentration of oxygen in the exhaust gas; it converts that data to voltage, and sends it to the ECM
- When the left bank heated oxygen sensor (front) begins to deteriorate, the heated oxygen sensor signal response deteriorates also.
- The ECM
DESCRIPTIONS OF MONITOR METHODS
Left bank heated oxygen sensor (front) circuit is switched to 5 volts intentionally when oxygen sensor output is low, and detects the malfunction if the output voltage changes to equal or greater than 4.5 volts. The above procedure is repeated when oxygen sensor is inactive.
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)
- Heated oxygen sensor heater (front) monitor
- Misfire monitor
- Fuel system monitor
Sensor (The sensor below is determined to be normal)
- Volume airflow sensor
- Engine coolant temperature sensor
- Intake air temperature sensor
- Barometric pressure sensor
- Throttle position sensor
DTC SET CONDITIONS
Logic Flow Chart:
Logic Flow Chart
Check Conditions
- 3 minutes or more have passed since the starting sequence was completed.
- Left bank heated oxygen sensor (front) signal voltage has continued to be 0.2 volt or lower.
- Engine coolant temperature is higher than 76 °C (169 °F).
- Engine speed is higher than 1,200 r/min.
- Volumetric efficiency is higher than 25 percent.
- Monitoring time: 7 seconds.
Judgment Criteria
- Input voltage supplied to the ECM
OBD-II DRIVE CYCLE PATTERN
Refer to, Diagnostic Function - OBD-II Drive Cycle - Procedure 6 - Other Monitor. OBD-II Drive Cycle Pattern Lists
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Left bank heated oxygen sensor (front) deteriorated.
- Open or shorted circuit in left bank heated oxygen sensor (front) output line, or harness damage.
- Open circuit in left bank heated oxygen sensor (front) ground line, or harness damage.
- ECM failed.
- PCM failed.
- Connector damage.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B
- MD998464: Test Harness
STEP 1. Using scan tool MB991958, check data list item 11: Heated Oxygen Sensor Bank 2, Sensor 1 (left front).
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Start the engine and run at idle.
3. Set scan tool MB991958 to the data reading mode for item 11, Heated Oxygen Sensor Bank 2, Sensor 1 (left front).
- Warming up the engine. When the engine is revved, the output voltage should be 0.6 to 1.0 volt.
- Warming up the engine. When the engine is idling, the output voltage should repeat 0.4 volt and 0.6 to 1.0 volt alternately.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/ Inspection Service Points.
NO: Go to Step 2.
STEP 2. Check the sensor output voltage at left bank heated oxygen sensor (front) connector B-24 by backprobing.
1. Do not disconnect the connector B-24.
2. Start the engine and run at idle.
3. Measure the voltage between terminal 4 and ground by backprobing.
- Warming up the engine. When the engine is 2,500 r/min, the output voltage should repeat 0 to 0.8 volt alternately.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 3.
NO: Go to Step 7.
STEP 3. Check the sensor output voltage at ECM connector C-62
1. Do not disconnect the connector C-62
2. Start the engine and run at idle.
3. Measure the voltage between terminal No. 71 and ground by backprobing.
- Warming up the engine. When the engine is 2,500 r/min, the output voltage should repeat 0 to 0.8 volt alternately.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 4.
NO: Go to Step 6.
STEP 4. Check connector B-24 at left bank heated oxygen sensor (front) and connector C-62 at ECM
Q: Is the connector in good condition?
YES: Go to Step 5.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 15.
STEP 5. Using scan tool MB991958, check data list item 11: Heated Oxygen Sensor Bank 2, Sensor 1 (left front).
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Start the engine and run at idle.
3. Set scan tool MB991958 to the data reading mode for item 11, Heated Oxygen Sensor Bank 2, Sensor 1 (left front).
- Warming up the engine. When the engine is revved, the output voltage should be 0.6 to 1.0 volt.
- Warming up the engine. When the engine is idling, the output voltage should repeat 0.4 volt and 0.6 to 1.0 volt alternately.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/ Inspection Service Points.
NO: Replace the ECM or PCM. Then go to Step 15.
STEP 6. Check connector B-24 at left bank heated oxygen sensor (front) and connector C-62 at ECM
Q: Is the connector in good condition?
YES: Repair harness wire between left bank heated oxygen sensor (front) connector B-24 (terminal No. 4) and ECM connector C-62 (terminal No. 71)
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 15.
STEP 7. Check connector B-24 at left bank heated oxygen sensor (front) for damage.
Q: Is the connector in good condition?
YES: Go to Step 8.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 15.
STEP 8. Check the continuity at left bank heated oxygen sensor (front) harness side connector B-24.
1. Disconnect the connector B-24 and measure at the harness side.
2. Check for the continuity between terminal No. 2 and ground.
- Should be less than 2 Ohms.
Q: Is the continuity normal?
YES: Go to Step 11.
NO: Go to Step 9.
STEP 9. Check connector C-58 at ECM
Q: Is the connector in good condition?
YES: Go to Step 10.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 15.
STEP 10. Check for open circuit and harness damage between left bank heated oxygen sensor (front) connector B-24 (terminal No. 2) and ECM connector C-58 (terminal No. 49)
Q: Is the harness wire in good condition?
YES: Replace the ECM or PCM. Then go to Step 15.
NO: Repair it. Then go to Step 15.
STEP 11. Check connector C-62 at ECM
Q: Is the connector in good condition?
YES: Go to Step 12.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 15.
STEP 12. Check for harness damage between left bank heated oxygen sensor (front) connector B-24 (terminal No. 2) and ECM connector C-58 (terminal No. 49)
Q: Is the harness wire in good condition?
YES: Go to Step 13.
NO: Repair it. Then go to Step 15.
STEP 13. Check for short circuit to ground and harness damage between left bank heated oxygen sensor (front) connector B-24 (terminal No. 4) and ECM connector C-62 (terminal No. 71)
Q: Is the harness wire in good condition?
YES: Go to Step 14.
NO: Repair it. Then go to Step 15.
STEP 14. Check the left bank heated oxygen sensor (front).
1. Disconnect the left bank heated oxygen sensor (front) connector B-24 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 80 °C (176 °F) or higher.
CAUTION: Be very careful when connecting the jumper wires; incorrect connection can damage the left bank heated oxygen sensor (front).
3. Use the jumper wires to connect terminal 1 (red clip) to the positive battery terminal and terminal 3 (blue clip) to the negative battery terminal.
4. Connect a digital volt meter between terminal 2 (black clip) and terminal 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 volt
Q: Is the voltage between 0.6 and 1.0 volt?
YES: Replace the ECM or PCM. Then go to Step 15.
NO: Replace the left bank heated oxygen sensor (front). Then go to Step 15.
STEP 15. 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 - Procedure 6 - Other Monitor. OBD-II Drive Cycle Pattern Lists
2. Check the diagnostic trouble code (DTC).
Q: Is DTC P0150 set?
YES: Retry the troubleshooting.
NO: The inspection is complete.