M/T

DTC P1131 - FRONT OXYGEN (A/F) SENSOR CIRCUIT MALFUNCTION (SHORT CIRCUIT)

DTC DETECTING CONDITION:
- Two consecutive driving cycles with fault

CAUTION: After repair or replacement of faulty parts, conduct CLEAR MEMORY MODE and INSPECTION MODE. Refer to How To Clear Diagnostic Trouble Codes.

Wiring Diagram:

WIRING DIAGRAM:

10BZ1: CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR.

1. Turn ignition switch to OFF.
2. Disconnect connector from ECM.

Connector & Terminal - [(B136) No.7 - Chassis Ground]:

3. Measure resistance of harness between ECM connector and chassis ground.

CHECK: Is the resistance more than 10 Ohms?

YES: Go to step 10BZ2.

NO: Repair ground short circuit in harness between ECM and front oxygen (A/F) sensor connector.

10BZ2: CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR

Connector & Terminal - [(B136) No.20 - Chassis Ground]:

Measure resistance of harness between ECM connector and chassis ground.

CHECK: Is the resistance more than 10 Ohms?

YES: Go to step 10BZ3.

NO: Repair ground short circuit in harness between ECM and front oxygen (A/F) sensor connector.

10BZ3: CHECK OUTPUT SIGNAL FOR ECM.

1. Connect connector to ECM.
2. Turn ignition switch ON.

Connector & Terminal - [(B136) No.7 (+) - Chassis Ground (-)]:

3. Measure voltage between ECM connector and chassis ground.

CHECK: Is the voltage more than 4.5 V?

YES: Go to step 10BZ4.

NO: Go to step 10BZ5.

10BZ4: CHECK OUTPUT SIGNAL FOR ECM.

Connector & Terminal - [(B136) No.7 (+) - Chassis Ground (-)]:

Measure voltage between ECM connector and chassis ground.

CHECK: Is the voltage more than 10 V?

YES: Repair battery short circuit in harness between ECM and front oxygen (A/F) sensor connector. After repair, replace ECM.

NO: Repair poor contact in ECM connector.

10BZ5: CHECK OUTPUT SIGNAL FOR ECM.

Connector & Terminal - [(B136) No.20 (+) - Chassis ground (-)]:

Measure voltage between ECM connector and chassis ground.

CHECK: Is the voltage more than 4.95 V?

YES: Go to step 10BZ6.

NO: Replace front oxygen (A/F) sensor.

10BZ6: CHECK OUTPUT SIGNAL FOR ECM.

Connector & Terminal - [(B136) No.20 (+) - Chassis ground (-)]:

Measure voltage between ECM connector and chassis ground.

CHECK: Is the voltage more than 10 V?

YES: Repair battery short circuit in harness between ECM and front oxygen (A/F) sensor connector. After repair, replace ECM.

NO: Repair poor contact in ECM connector.