P0153

Left Bank Heated Oxygen Sensor (front) Circuit:

Connectors:

DTC P0153: Heated Oxygen Sensor Circuit Slow Response (bank 2, sensor 1)

CIRCUIT OPERATION
- A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the ECM (terminal No. 71) or PCM (terminal No. 71) from the output terminal (terminal No. 4) of the left bank heated oxygen sensor (front).
- Terminal No. 2 of the left bank heated oxygen sensor (front) is grounded with ECM (terminal No. 49) or PCM (terminal No. 57) .

TECHNICAL DESCRIPTION
- The left bank heated oxygen sensor (front) detects the concentration of oxygen in the exhaust gas; it converts those data to voltage, and sends it to the ECM or PCM .
- When the heated oxygen sensor (front) begins to deteriorate, the heated oxygen sensor signal response deteriorates also.
- The ECM or PCM forcibly varies the air/fuel mixture to make it leaner and richer, and checks the response speed of the left bank heated oxygen sensor (front). In addition, the ECM or PCM also checks for an open circuit in the left bank heated oxygen sensor (front) output line.

DESCRIPTIONS OF MONITOR METHODS
Left bank heated oxygen sensor (front) rich/lean switching frequency is under specified value.

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

Logic Flow Chart:

DTC SET CONDITIONS

Check Conditions
- Engine coolant temperature is higher than 50 °C (122 °F).
- Engine speed is between 1,250 and 3,000 rpm.
- Volumetric efficiency is between 20 and 60 percent at AT.
- Volumetric efficiency is between 18 and 60 percent at MT.
- Under the closed loop air/fuel control.
- The throttle valve is open.
- Short-term fuel trim is higher than -30 percent and lower than +25 percent.
- More than 3 seconds have elapsed after the above mentioned conditions have been met.
- The ECM or PCM monitors for this condition for 7 cycles of 12 seconds each during the drive cycle.

Judgment Criteria
- The left bank heated oxygen sensor (front) sends "lean" and "rich" signals alternately 11 times or less for 12 seconds.

NOTE: If the sensor switch time is longer than the Judgment Criteria due to the MUT-II OBD-II test Mode - H02S Test Results, it is assumed that the heated oxygen sensor has deteriorated. If it is short, it is assumed that the harness wire is broken or has & short circuit. If the heated oxygen sensor signal voltage has not changed even once (lean/rich) after the DTC was erased, the sensor switch time will display as 0 seconds.

OBD-LL DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Procedure 4 - Heated Oxygen Sensor Monitor.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are: )
- Left bank heated oxygen sensor (front) deteriorated.
- Connector damage.
- PCM failed.

DIAGNOSIS

Required Special Tool:
- MB991502: Scan Tool (MUT-II)
- MD998464: Test Harness

STEP 1. Using scan tool MB991502, check data list item 11: Heated Oxygen Sensor Bank 2, Sensor 1 (left front).

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.

1. Connect scan tool MB991502 to the data link connector.
2. Start the engine and run at idle.
3. Set scan tool MB991502 to the data reading mode for item 11, Heated Oxygen Sensor Bank 2, Sensor 1 (left front).
4. Warm up the engine, 2,500 rpm.
- Output voltage repeats 0.4 volt or less and.6 - 1.0 volt 10 times or more within 10 seconds.

5. 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 INTRODUCTION, How to Use Troubleshooting/Inspection Service Points.
NO: Go to Step 2.

STEP 2. 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 right bank heated oxygen sensor (front).

3. Use the jumper wires to connect terminal No. 1 (red clip) to the positive battery terminal and terminal No. 3 (blue clip) to the negative battery terminal.
4. Connect a digital volt 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 volt

Q: Is the voltage between 0.6 and 1.0 volt?

YES: Go to Step 3.
NO: Replace the left bank heated oxygen sensor (front).Then go to Step 4.

STEP 3. Check harness connector B-24 at left bank heated oxygen sensor (front) and harness connector C-118, C-122 at ECM or C-115, C-119 at PCM for damage.

Q: Is the harness connector in good condition?

YES: Replace the PCM. Then go to Step 4.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 4.

STEP 4. 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 4 - Heated Oxygen Sensor Monitor.
2. Check the diagnostic trouble code (DTC).

Q: Is DTC P0153 set?

YES: Retry the troubleshooting.
NO: The inspection is complete.