P0153
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 [M/T] or the PCM [A/T] (terminal No. 91) 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 [M/T] or PCM [A/T] (terminal No. 79).
- The ECM [M/T] or the PCM [A/T] applies an offset voltage of 0.5 volt to terminal No. 2 of the left bank heated oxygen sensor (front).
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 inputs the resulting signals to the ECM [M/T] or the PCM [A/T].
- When the left bank heated oxygen sensor (front) begins to deteriorate, the left bank heated oxygen sensor signal response becomes poor.
- The ECM [M/T] or the PCM [A/T] also checks for the left bank heated oxygen sensor (front) rich/lean switch frequency.
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)
- Mass airflow sensor
- Engine coolant temperature sensor
- Intake air temperature sensor
- Barometric pressure sensor
- Throttle position sensor
- Accelerator pedal position sensor
DTC SET CONDITIONS
Logic Flow Chart
Check Conditions
- Engine coolant temperature is higher than 50°C (122°F).
- Engine speed is between 1,500 and 3,000 r/min [M/T] or 1,300 and 3,000 r/min [A/T].
- Volumetric efficiency is between 12 and 60 [M/T] or 20 and 60 [A/T] percent.
- Under the closed loop air/fuel control.
- The accelerator pedal depressed.
- Short-term fuel trim is at between -30 and +25 percent.
- More than 2 seconds have elapsed after the above mentioned conditions have been met.
- During the drive cycle, the ECM [M/T] or the PCM [A/T] performs monitoring with the accumulated total time of 12 seconds, 7 times [M/T] or 5 times [A/T].
Judgement Criteria
- The average of the left bank heated oxygen sensor (front) rich/lean switching frequency is less than 10 times for the accumulated time of 12 seconds.
- The left bank heated oxygen sensor (front) rich/lean switching frequency is less than 20 times for the accumulated time of 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 seconds.
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:)
- Left bank heated oxygen sensor (front) deteriorated.
- Connector damage.
- ECM failed. [M/T]
- PCM failed. [A/T]
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991910: Main Harness A
- MD998464: Test Harness
STEP 1. Using scan tool MB991958, check data list item AE: 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 AE, Heated Oxygen Sensor Bank 2, Sensor 1 (left 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. How to Cope With Intermittent Malfunctions.
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 temperature reaches 80°C (176°F) or higher.
(3)Rev the engine for 5 minutes or more with the engine speed of 2,500 r/min.
(4)Connect a digital voltage meter between terminal No. 2 (black clip) and terminal No. 4 (white clip).
(5)Warm up engine, 2,500 r/min.
- Output voltage repeats 0 - 0.4 volt and 0.6 - 1.0 volt 10 times or more within 10 seconds.
(6)
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 through 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 sensor operating properly?
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 B-20, B-21 at ECM [M/T] or PCM [A/T] for damage.
Q. Is the harness connector in good condition?
YES Replace the ECM or the PCM. When the ECM or the PCM is replaced, register the encrypted code. Immobilizer System.
Then go to Step 4.
NO Repair or replace it. 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 - Pattern 1 OBD-II Drive Cycle.
(2)Check the diagnostic trouble code (DTC).
Q. Is DTC P0153 set?
YES Retry the troubleshooting.
NO The inspection is complete.