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. 54) 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. 55).
The ECM applies an off set voltage of 0.5 volt to terminal No. 2 of the right bank oxygen sensor (front).
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.
When the right bank heated oxygen sensor (front) begins to deteriorate, the heated oxygen sensor signal response becomes poor.
The ECM also checks for the right bank heated oxygen sensor (front) rich learn switching frequency.
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
Sensor (The sensor below is determined to be normal)
Engine coolant temperature 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 between 1,250 and 3,500 r/min.
Volumetric efficiency is between 25 and 65 percent.
Under the closed loop air/fuel control.
The accelerator pedal is open.
Short-term fuel trim is between -25 and +25 percent. More than 2 seconds have elapsed after the above mentioned conditions have been met.
The ECM monitors for this condition for 5 cycles of 12 seconds each during the drive cycle.
Judgement Criterion
The average of the right bank heated oxygen sensor (front) rich/lean switching frequency is less than 13 times per 12 seconds.
NOTE: If the sensor switching frequency is lower than the Judgment Criteria due to the M.U.T.-III OBD-II test Mode - HO2S Test Results, it is assumed that the heated oxygen sensor has deteriorated. If it is higher, 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 second.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1. OBD-II Drive Cycle
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are: )
Right bank heated oxygen sensor (front) deteriorated.
ECM failed.
DIAGNOSIS
Required Special Tools:
MB991316: Test Harness
STEP 1. 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 4,500 r/min.
4. Connect a digital voltage meter between terminal No. 2 (black clip) and terminal No. 4 (white clip).
5. Warn up the engine, 2,500 r/min.
Output voltage repeats 0 - 0.4 volt or less and 0.6 - 1.0 volts 13 times or more within 12 seconds.
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 sufficiently high temperature [of approximate 400 °C (752 °F) or more] is not reached although the heated oxygen sensor is normal, the output voltage would be possibly low although 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 sensor operating properly?
YES: Go to Step 2.
NO: Replace the right bank heated oxygen sensor (front). Then go to Step 2.
STEP 2. 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 1. OBD-II Drive Cycle
2. Check the diagnostic trouble code (DTC).
Q: Is DTC P0133 set?
YES: Replace the ECM. When the ECM is replaced, register the ID code. Refer to ID Code Registration Judgment Table
NO: It can be assumed that this malfunction is intermittent.