P0133

DTC P0133: Heated Oxygen Sensor Circuit Slow Response (bank 1, sensor 1)

Right Bank Heated Oxygen Sensor (front) Circuit Part 1:

Right 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. 72) or PCM (terminal No. 72) from the output terminal (terminal No. 4) of the right bank heated oxygen sensor (front).
- Terminal No. 2 of the right bank heated oxygen sensor (front) is grounded with ECM (terminal No. 49) or PCM (terminal No. 57) .

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

DESCRIPTIONS OF MONITOR METHODS
Right 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

DTC SET CONDITIONS

Logic Flow Chart:

Logic Flow Chart

Check Conditions
- Engine coolant temperature is higher than 50 °C (122 °F).
- Engine speed is at between 1,250 and 3,000 r/min.
- 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 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 second each during the drive cycle.

Judgment Criteria
- The right 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-III 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 is damaged or has a 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-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Procedure 4 - Heated Oxygen Sensor Monitor. OBD-II Drive Cycle Pattern Lists

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

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B
- MB998464:Test Harness

STEP 1. Using scan tool MB991958, check data list item 39: Heated Oxygen Sensor Bank 1, Sensor 1 (right 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 39, Heated Oxygen Sensor Bank 1, Sensor 1 (right front).
4. Warm up the engine, 2,500 r/min.
- Output voltage repeats 0.4 volt or less and 0.6 - 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 How to Use Troubleshooting/ Inspection Service Points.

NO: Replace the right bank heated oxygen sensor (front). Then go to Step 2.

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

1. Disconnect the right bank heated oxygen sensor (front) connector B-27 and connect test harness special tool, MD998464, 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.

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 right 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 right bank heated oxygen sensor (front). Then go to Step 4.

STEP 3. Check harness connector B-27 at right bank heated oxygen sensor (front) and harness connector C-58, C-62 at ECM or C-55, C-59 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. OBD-II Drive Cycle Pattern Lists
2. Check the diagnostic trouble code (DTC).

Q: Is DTC P0133 set?

YES: Retry the troubleshooting.

NO: The inspection is complete.