P0134

O(2) Sensor Circuit No Activity Detected (sensor 1)
- Refer to DTC P0130 Heated Oxygen Sensor (front) Circuit.
- Refer to DTC P0201, P0202, P0203, P0204 - Injector Circuit.

CIRCUIT OPERATION
- Refer to DTC P0130 Heated Oxygen Sensor (front) Circuit.
- Refer to DTC P0201, P0202, P0203, P0204 - Injector Circuit.

TECHNICAL DESCRIPTION
- The 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 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 heated oxygen sensor (front). In addition, the ECM or PCM also checks for an open circuit in the heated oxygen sensor (front) output line.

DTC SET CONDITIONS

Check Area
- Thirty seconds or more have passed since the starting sequence was completed.
- Engine coolant temperature is higher than 81 °C (178 °F).
- Engine speed is at between 1800 and 3500 r/min.
- Volumetric efficiency is at between 16 and 62 percent.
- Under the closed loop air/fuel control.
- Monitoring time 30 seconds.

Judgment Criteria
- Multiport fuel injection system does not enter the closed loop control within about 30 seconds of meeting all criteria above.
- Only one monitor during one drive cycle.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Heated oxygen sensor (front) deteriorated.
- Open circuit in heated oxygen sensor (front) output line.
- Open circuit in heated oxygen sensor (front) ground line.
- ECM failed.
- PCM failed.

DIAGNOSIS

Required Special Tools
MD998464: Test Harness

STEP 1. Check the exhaust leaks.

Q: Are there any abnormalities?

YES: Go to Step 2.

NO: Repair it. Then go to Step 11.

STEP 2. Check the intake system vacuum leak.

Q: Are there any abnormalities?

YES: Go to Step 3.

NO: Repair it. Then go to Step 11.

STEP 3. Check connector B-17 at the heated oxygen sensor (front) for damage.

Q: Is the connector in good condition?

YES: Go to Step 4.

NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 11.

STEP 4. Check the heated oxygen sensor (front).

1. Disconnect the heated oxygen sensor (front) connector B-17 and connect test harness special tool, M0998464 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 1 (red clip) to the positive battery terminal and terminal 3 (blue clip) to the negative battery terminal.
4. Connect a digital volt meter between terminal 2 (black clip) and terminal 4 (white clip).

5. While repeatedly revving the engine, measure the heated oxygen sensor (front) output voltage.

Standard value: 0.6 - 1.0 V

Q: Is the voltage at the standard value?

YES: Go to Step 5.

NO: Replace the heated oxygen sensor (front). Then go to Step 13.

STEP 5. Check connector B-01, B-02, B-05, B-06 at injector for damage.

Q: Is the connector in good condition?

YES: Go to Step 6.

NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 11.

STEP 6. Check the injector.
1. Disconnect each injector connector.
2. Measure the resistance between injector side connector terminal 1 and 2.

Standard value: 13 - 16 Ohms [at 20 °C (68 °F)]

Q: Is the resistance standard value?

YES: Go to Step 7.

NO: Replace the injector. Then go to Step 11.

STEP 7. Check connector C-109, C-120 at ECM or connector C-110, C-117 at PCM for damage.

Q: Is the connector in good condition?

YES: Go to Step 8.

NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 11.

STEP 8. Check for harness damage between heated oxygen sensor (front) connector B-17 terminal 4 and ECM connector C-120 terminal 76 or PCM connector C-117 terminal 71 .

Q: Is the harness wire in good condition?

YES: Go to Step 9.

NO: Repair it. Then go to Step 11.

STEP 9. Check for harness damage between injector connector and ECM connector or PCM connector.
a. Check the harness wire between injector connector B-01 terminal 2 and ECM connector C-109 terminal 1 or PCM connector C-110 terminal 1 when checking No.1 cylinder.
b. Check the harness wire between injector connector B-02 terminal 2 and ECM connector C-109 terminal 14 or PCM connector C-110 terminal 9 when checking No.2 cylinder.
c. Check the harness wire between injector connector B-05 terminal 2 and ECM connector C-109 terminal 2 or PCM connector C-110 terminal 24 when checking No.3 cylinder.
d. Check the harness wire between injector connector B-06 terminal 2 and ECM connector C-109 terminal 15 or PCM connector C-110 terminal 2 when checking No.4 cylinder.

Q: Is the harness wire in good condition?

YES: Go to Step 10.

NO: Repair it. Then go to Step 11.

STEP 10. Check the fuel pressure.

Q: Is the fuel pressure normal?

YES: Replace the ECM or PCM. Then go to Step 11.

NO: Repair it. Then go to Step 11.

STEP 11. Test the OBD-II drive cycle.
1. Carry out a test drive with the drive cycle pattern. Refer to Procedure 6 - Other Monitor.
2. Check the diagnostic trouble code(DTC).

Q: Is the DTC P0134 is output?

YES: Retry the troubleshooting.

NO: The inspection is complete.