P0134
DTC P0134: Heated Oxygen Sensor Circuit No Activity Detected (Sensor 1)Heated Oxygen Sensor Circuit No Activity Detected (sensor 1)
- Refer to DTC P0130 Heated Oxygen Sensor Circuit (sensor 1).
- Refer to DTC P0201 - Injector Circuit - Cylinder 1.
- Refer to DTC P0202 - Injector Circuit - Cylinder 2.
- Refer to DTC P0203 - Injector Circuit - Cylinder 3.
- Refer to DTC P0204 - Injector Circuit - Cylinder 4.
CIRCUIT OPERATION
- A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the ECM (terminal No.76)
- Terminal No.2 of the heated oxygen sensor (front) is grounded with ECM (terminal No. 92)
- The injector power is supplied from the MFI relay (terminal No.1).
- The ECM
TECHNICAL DESCRIPTION
- The ECM
- If the heated oxygen sensor (front) has deteriorated, corrections will be made by the heated oxygen sensor (rear).
- DTC P0134 becomes stored in memory if a failure is detected in the above air/fuel ratio feedback control system.
DESCRIPTIONS OF MONITOR METHODS
Heated oxygen sensor (front) output voltage does not cross 0.5 volt within specified period.
MONITOR EXECUTION
Continuous
MONITOR EXECUTION CONDITIONS
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)
- 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
- 20 seconds or more have passed since the starting sequence was completed.
- Engine coolant temperature is higher than 76 °C (169 °F).
- Engine speed is at higher than 1,200 rpm.
- Volumetric efficiency is at between 30 and 80 percent.
- Throttle position sensor output voltage is lower than 4.3 volts.
- Except while fuel is being shut off.
- Monitoring time: 30 seconds.
Judgment Criteria
- Heated oxygen sensor (front) output voltage does not get across 0.5 volt within about 30 seconds.
OBD-LL Drive Cycle Pattern
Refer to Diagnostic Function - OBD-II drive Cycle-Procedure 6 - Other Monitor.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Heated oxygen sensor (front) deteriorated.
- Harness damage in heated oxygen sensor (front) output line.
- Heated oxygen sensor (rear) deteriorated.
NOTE: When the 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 heated oxygen sensor (rear). If the heated oxygen sensor (rear) responds poorly because it has deteriorated, it will improperly correct the heated oxygen sensor (front). Thus, even when closed loop control is being effected, the fluctuation of the heated oxygen sensor (front) output voltage decreases, without intersecting with 0.5 volt. As a result, there is a possibility of DTC P0134 becoming registered.
- Connector damage.
- Harness damage in injector circuit.
- Injector failed.
- ECM failed.
- PCM failed.
- Exhaust leak.
- Incorrect fuel pressure.
- Intake system vacuum leak.
DIAGNOSIS
Required Special Tools:
- MB9g1502: Scan Tool (MUT-II)
- MD998464: Test Harness
STEP 1. Using scan tool MB991502, check data list item 59: Heated Oxygen Sensor (rear).
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 59, Heated Oxygen Sensor (rear).
- Warming 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: Go to Step 2.
NO: Refer to DTC P0136-Heated Oxygen Sensor Circuit (sensor 2), DTC P0137 - Heated Oxygen Sensor Circuit Low Voltage (sensor 2), DTC P0138 - Heated Oxygen Sensor Circuit High Voltage (sensor 2), DTC P0139 Heated Oxygen Sensor Circuit Slow Response (sensor 2).
STEP 2. Check the exhaust leaks.
Q: Are there any abnormalities?
YES: Go to Step 3.
NO: Repair it. Then go to Step 12.
STEP 3. Check the intake system vacuum leak.
Q: Are there any abnormalities?
YES: Go to Step 4.
NO: Repair it. Then go to Step 12.
STEP 4. Check connector B-17 at the heated oxygen sensor (front) for damage.
Q: Is the connector in good condition?
YES: Go to Step 5.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 12.
STEP 5. Check the heated oxygen sensor (front).
1. Disconnect the heated oxygen sensor (front) connector B-17 and connect test harness special tool, MD998464 to the connector on the 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 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 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 6.
NO: Replace the heated oxygen sensor (front). Then go to Step 12.
STEP 6. Check connectors B-01, B-02, B-05, B-06 at injector for damage.
Q: Is the connector in good condition?
YES: Go to Step 7.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 12.
STEP 7. Check the injector.
1. Disconnect each injector connector.
2. Measure the resistance between injector side connector terminals No.1 and No.2.
Standard value: 13 - 16 ohms @ 20 °C (68 °F)
Q: Is the resistance between 13 and 16 ohms @ 20 °C (68 °F)]?
YES: Go to Step 8.
NO: Replace the injector. Then go to Step 12.
STEP 8. Check connector C-109, C-120 at ECM
Q: Is the connector in good condition?
YES: Go to Step 9.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 12.
STEP 9. Check for harness damage between heated oxygen sensor (front) connector B-17 (terminal No. 4) and ECM connector C-120 (terminal No. 76)
Q: Is the harness wire in good condition?
YES: Go to Step 10.
NO: Repair it. Then go to Step 12.
STEP 10. Check for harness damage between injector connector B-01, B-02, B-05, B-06 and ECM connector C- 109
a. Check the harness wire between injector connector B-01 (terminal No.2) and ECM connector C-109 (terminal No.1)
b. Check the harness wire between injector connector B-02 (terminal No.2) and ECM connector C-109 (terminal No. 14)
c. Check the harness wire between injector connector B-05 (terminal No.2) and ECM connector C-109 (terminal No.2)
d. Check the harness wire between injector connector B-06 (terminal No.2) and ECM connector C-109 (terminal No. 15)
Q: Is the harness wire in good condition?
YES: Go to Step 11.
NO: Repair it. Then go to Step 12.
STEP 11. Check the fuel pressure.
Refer to On-vehicle Service - Fuel Pressure Test.
Q: Is the fuel pressure normal?
YES: Replace the ECM or PCM. Then go to Step 12.
NO: Repair it. Then go to Step 12.
STEP 12. Test the OBD-II drive cycle.
1. Carry out a test drive with the drive cycle pattern. Refer to Trouble Code Diagnosis - OBD-II Drive Cycle - Procedure 6 - Other Monitor.
2. Check the diagnostic trouble code (DTC).
Q: Is DTC P0134 set?
YES: Retry the troubleshooting.
NO: The inspection is complete.