P1139

DTC P1139 - FRONT OXYGEN (A/F) SENSOR #1 HEATER CIRCUIT RANGE/PERFORMANCE PROBLEM

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

10CD1: CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR.
1. Start engine, and warm-up the engine.
2. Turn ignition switch to OFF.
3. Disconnect connectors from ECM and front oxygen (A/F) sensor.

Connector & Terminal - [(B134) No.22 - (B18) No.4]:

4. Measure resistance of harness between ECM and front oxygen (A/F) sensor connector.

CHECK: Is the resistance less than 1 Ohm?

YES: Go to step 10CD2.

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

10CD2: CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR.

Connector & Terminal - [(B134) No.7 - (B18) No.1]:

Measure resistance of harness between ECM and front oxygen (A/F) sensor connector.

CHECK: Is the resistance less than 1 ohms?

YES: Go to step 10CD3.

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

10CD3: CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR.

Connector & Terminal - [(B136) No.20 - (B18) No.3]:

Measure resistance of harness between ECM and front oxygen (A/F) sensor connector.

CHECK: Is the resistance less than 1 Ohm?

YES: Go to step 10CD4.

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

10CD4: CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR.

Connector & Terminal - [(B136) No.3 - (B18) No.2]:

Measure resistance of harness between ECM and front oxygen (A/F) sensor connector.

CHECK: Is the resistance less than 1 Ohm?

YES: Go to step 10CD5.

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

10CD5: CHECK FRONT OXYGEN (A/F) SENSOR.

Terminals - [No.2 - No.4]:

Measure resistance between front oxygen (A/F) sensor connector terminals.

CHECK: Is the resistance less than

YES: Go to step 10CD6.

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

10CD6: CHECK POOR CONTACT.
Check poor contact in ECM and front oxygen (A/F) sensor connector.

CHECK: Is there poor contact in ECM or front oxygen (A/F) sensor connector?

YES: Repair poor contact in ECM or front oxygen (A/F) sensor connector.

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