P0154
DTC P0154: Heated Oxygen Sensor Circuit No Activity Detected (bank 2, sensor 1)
Heated Oxygen Sensor Circuit No Activity Detected (bank 2, sensor 1) Circuit
- Refer to DTC P0151 - Heated Oxygen Sensor Circuit Low Voltage (bank 2, sensor 1) P0151.
- Refer to DTC P0202 - Injector Circuit Malfunction - Cylinder 2 P0202, DTC P0204 - Injector Circuit Malfunction - Cylinder 4 P0204, DTC P0206 - Injector Circuit Malfunction - Cylinder 6 P0206.
CIRCUIT OPERATION
- Refer to DTC P0151 - Heated Oxygen Sensor Circuit Low Voltage (bank 2, sensor 1) P0151.
- Refer to DTC P0202 - Injector Circuit Malfunction - Cylinder 2 P0202, DTC P0204 - Injector Circuit Malfunction - Cylinder 4 P0204, DTC P0206 - Injector Circuit Malfunction - Cylinder 6 P0206.
TECHNICAL DESCRIPTION
- The ECM effects air/fuel ratio feedback control in accordance with the signals from the left bank heater oxygen sensor (front).
- If the left bank heated oxygen sensor (front) has deteriorated, corrections will be made by the heated oxygen sensor (rear).
- DTC P0154 becomes stored in memory if a failure is detected in the above air/fuel ratio feedback control system.
DESCRIPTIONS OF MONITOR METHODS
Left bank heated oxygen sensor (front) output voltage does not exceed lean/rich criteria
(about 0.5 volt) within specified period.
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)
- Misfire 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
DTC SET CONDITIONS
Logic Flow Chart
Check Conditions
- More than 350 seconds have passed since the engine starting sequence was completed.
- Engine coolant temperature is higher than 7°C (45°F).
- Engine speed is higher than 1,200 r/min.
- Volumetric efficiency is higher than 30 percent.
- Throttle position sensor output voltage is lower than 4 volts.
- Except while fuel is being shut off.
- Monitoring time: 30 seconds.
Judgement Criterion
- Left bank heated oxygen sensor (front) output voltage does not get across lean/rich criteria (about 0.5 volt) within about 30 seconds.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 12 Monitors, Trips, Drive Cycles and Readiness Codes.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Left bank heated oxygen sensor (front) deteriorated.
- Harness damage.
NOTE:
When the left bank heated oxygen sensor (front) begins to deteriorate, the heated oxygen sensor output voltage will deviate from the voltage when the sensor was new (normally 0.5 volt at stoichiometric ratio). This deviation will be corrected by the left bank heated oxygen sensor (rear).
If the left bank heated oxygen sensor (rear) responds poorly because it has deteriorated, it will improperly correct the left bank heated oxygen sensor (front). Thus, even when closed loop control is being effected, the fluctuation of the left bank heated oxygen sensor (front) output voltage decreases, without intersecting with 0.5 volt. As a result, there is a possibility of DTC P0154 becoming registered.
- Open circuit in right bank injector.
- Connector damage.
- Exhaust leak.
- Air drawn in from gaps in gasket, seals, etc.
- Incorrect fuel pressure.
- ECM failed.
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 AF:
Heated Oxygen Sensor Bank 2, Sensor 2 (left rear).
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 AF, Heated Oxygen Sensor Bank 2, Sensor 2 (left rear).
- Warm up the engine. When the engine is revved, the output voltage should repeat 0 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 Refer to DTC P0157 - Heated Oxygen Sensor Circuit Low Voltage (bank 2, sensor 2) P0157, DTC P0158 Heated Oxygen Sensor Circuit High Voltage
(bank 2, sensor 2) P0158, DTC P0159 - Heated Oxygen Sensor Circuit Slow Response (bank 2, sensor 2) P0159, DTC P0160 - Heated Oxygen Sensor Circuit No Activity Detected (bank 2, sensor 2) P0160.
NO Go to Step 2.
STEP 2. Check harness connector B-14 at the left bank heated oxygen sensor (front) and harness connector B-10 at the ECM for damage.
Q. Is the harness connector in good condition?
YES Go to Step 3.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 12.
STEP 3. Check the left bank heated oxygen sensor (front).
(1)Disconnect the left bank heated oxygen sensor (front) connector B-14 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 4,500 r/min.
(4)Connect a digital voltage 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 volts
(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 it 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 though the 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 voltage between 0.6 and 1.0 volts?
YES Go to Step 4.
NO Replace the left bank heated oxygen sensor (front). Then go to Step 12.
STEP 4. Check for harness between the left heated oxygen sensor (front) connector B-14 and the ECM connector B-10.
(1)Disconnect the left bank heated oxygen sensor (front) connector B-14 and the ECM connector B-10.
(2)Measure the resistance between the heated oxygen sensor connector B-14 and the ECM connector B-10.
(3) 1. Connector B-14 (terminal No. 2) and connector B-10 (terminal No. 39).
2. Connector B-14 (terminal No. 4) and connector B-10 (terminal No. 38).
- Should be less than 2 ohms.
(4)Check for the continuity between the oxygen sensor connector B-14 and ground.
3. Connector B-14 (terminal No. 2) and ground
4. Connector B-14 (terminal No. 4) and ground
- Not continuity.
Q. Is the harness wire in good condition?
YES Go to Step 5.
NO Repair it. Harness Connector Inspection.
Then go to Step 12.
STEP 5. Check harness connector B-115, B-116, B-120 at left bank injector for damage.
(1)Remove the intake manifold.
(2)Check the left bank injector connector for damage.
Q. Is the harness connector in good condition?
YES Go to Step 6.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 12.
STEP 6. Check the left bank injector.
(1)Disconnect each left bank injector connector.
(2)Measure the resistance between injector side connector terminal No. 1 and No. 2.
Standard value: 10.5 - 13.5 ohms [at 20°C (68°F)]
Q. Is the measured resistance between 10.5 and 13.5 ohms [at 20°C (68°F)]?
YES Go to Step 7.
NO Replace the injector. Then go to Step 12.
STEP 7. Check for harness between the left bank injector connector B-115, B-116, B-120 and the ECM connector B-10.
(1)Disconnect the left bank injector connector B-115, B-116, B-120 and the ECM connector B-10.
(2)Measure the resistance between the left bank injector connector B-115, B-116, B-120 and the ECM connector B-10.
(3) 5. Connector B-115 (terminal No. 2) and connector B-10 (terminal No. 51) at No. 6 Cylinder injector.
6. Connector B-116 (terminal No. 2) and connector B-10 (terminal No. 19) at No. 4 Cylinder injector.
7. Connector B-120 (terminal No. 2) and connector B-10 (terminal No. 3) at No. 2 Cylinder injector.
- Should be less than 2 ohms.
Q. Is the harness wire in good condition?
YES Go to Step 8.
NO Repair it. Harness Connector Inspection.
Then go to Step 12.
STEP 8. Check the fuel pressure.
Refer to On-vehicle Service - Fuel Pressure Test Testing and Inspection.
Q. Is the fuel pressure normal?
YES Go to Step 9.
NO Repair it. Then go to Step 12.
STEP 9. Check for exhaust leaks.
Q. Are there any abnormalities?
YES Repair it. Then go to Step 12.
NO Go to Step 10.
STEP 10. Check for intake system vacuum leak.
Q. Are there any abnormalities?
YES Repair it. Then go to Step 12.
NO Go to Step 11.
STEP 11. Check the trouble symptoms.
(1)Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 12 Monitors, Trips, Drive Cycles and Readiness Codes.
(2)Check the diagnostic trouble code (DTC).
Q. Is DTC P0154 set?
YES Replace the ECM. When the ECM is replaced, register the ID code. Refer to ID registration procedure manual - ID codes registration judgement table [Vehicles with KOS] or ID registration procedure manual - ID codes registration judgement table [Vehicles with WCM]. Then go to Step 12.
NO It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
STEP 12. 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 12 Monitors, Trips, Drive Cycles and Readiness Codes.
(2)Check the diagnostic trouble code (DTC).
Q. Is DTC P0154 set?
YES Retry the troubleshooting.
NO The inspection is complete.