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M/T

DTC P1132 - FRONT OXYGEN (A/F) SENSOR HEATER CIRCUIT LOW INPUT

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

10CA1: CHECK ANY OTHER DTC ON DISPLAY.

CHECK: Does the Subaru Select Monitor or OBD-II general scan tool indicate DTC P1132 and P0141 at the same time?

YES: Go to step 10CA2.

NO: Go to step 10CA5.

10CA2: CHECK GROUND CIRCUIT OF ECM.

Connector & Terminal - [(B134) No.35 - Chassis Ground]:





Measure resistance of harness between ECM connector and chassis ground.

CHECK: Is the resistance less than 5 Ohms?

YES: Go to step 10CA6.

NO: Repair harness and connector.

NOTE: In this case, repair the following:
- Open circuit in harness between ECM and engine ground terminal
- Poor contact in ECM connector Poor contact in coupling connector (B22).

10CA3: CHECK GROUND CIRCUIT OF ECM.

Connector & Terminal - [(B134) No.34 - Chassis Ground]:





1. Repair harness and connector.

NOTE: In this case, repair the following:
- Open circuit in harness between ECM and engine ground terminal
- Poor contact in ECM connector
- Poor contact in coupling connector (B22)

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

CHECK: Is there resistance less than 5 Ohms?

YES: Go to step 10C6.

NO: Repair harness and connector.

NOTE: In this case, repair the following:
- Open circuit in harness between ECM and engine ground terminal
- Poor contact in ECM connector Poor contact in coupling connector (B22)

10CA4: CHECK POWER SUPPLY CIRCUIT OF ECM.
1 .Disconnect connectors from ECM.
2. Turn ignition switch to ON.

Connector & Terminal - [(B136) No.3 (+) - (B134) No.34 (-)]:





3. Measure power supply voltage between ECM connector terminals.

CHECK: Is the voltage more than 8 V?

YES: Go to step 10CA3.

NO: Repair open or ground short circuit in harness of power supply circuit.

10CA5: CHECK POWER SUPPLY CIRCUIT OF ECM.

Connector & Terminal - [(B136) No.3 (+) - (B134) No.35 (-)]:





Measure power supply voltage between ECM connector terminals.

CHECK: Is the voltage more than 8 V?

YES: Go to step 10CA4.

NO: Repair open or ground short circuit in harness of power supply circuit.

10CA6: CHECK CURRENT DATA.
1. Start engine
2. Read data of front oxygen (A/F) sensor heater current using Subaru Select Monitor or OBD-II general scan tool.

NOTE:
- Subaru Select Monitor For detailed operation procedure, refer to the "READ CURRENT DATA SHOWN ON DISPLAY FOR ENGINE". Refer to Normal Scan Data Values.
- OBD-II scan tool
For detailed operation procedures, refer to the OBD-II General Scan Tool Instruction Manual.

CHECK: Is the value more than 0.2 A?

YES: Repair poor contact in connector.

NOTE: In this case, repair the following:
- Poor contact in front oxygen (A/F) sensor connector
- Poor contact in ECM connector

NO: Go to step 10CA7.

10CA7: CHECK OUTPUT SIGNAL FROM ECM.

1. Start and idle the engine.

Connector & Terminal - [(B134) No.22 (+) - Chassis ground (-)]:





2. Measure voltage between ECM connector and chassis ground.

CHECK: Is the voltage less than 1.0 V?

YES: Go to step 10CA9.

NO: Go to step 10CA8.

10CA8: CHECK OUTPUT SIGNAL FROM ECM.

Connector & Terminal - [(B134) No.22 (+) - Chassis ground (-)]:





Measure voltage between ECM connector and chassis ground.

CHECK: Does the voltage change less than 1.0 V by shaking harness and connector of ECM while monitoring the value with voltage meter?

YES: Repair poor contact in ECM connector.

NO: Go to step 10CA9.

10CA9: CHECK OUTPUT SIGNAL FROM ECM.

Connector & Terminal - [(B134) No.23 (+) - Chassis ground (-)]:





Measure voltage between ECM connector and chassis ground.

CHECK: Is the voltage less than 1.0 V?

YES: Go to step 11CA11.

NO: Go to step 10CA10.

10CA10: CHECK OUTPUT SIGNAL FROM ECM.

Connector & Terminal - [(B134) No.23 (+) - Chassis ground (-)]:





Measure voltage between ECM connector and chassis ground.

CHECK: Does the voltage change less than 1.0 V by shaking harness and connector of ECM while monitoring the value with voltage meter?

YES: Repair poor contact in ECM connector.

NO: Go to step 10CA11.

10CA11: CHECK POWER SUPPLY TO FRONT OXYGEN (A/F) SENSOR.

1. Turn ignition switch to OFF.
2. Disconnect connector from front oxygen (A/F) sensor.
3. Turn ignition switch to ON.

Connector & Terminal - [(B18) No.2 (+) - Engine Ground (-)]:





4. Measure voltage between front oxygen (A/F) sensor connector and engine ground.

CHECK: Is the voltage more than 10 V?

YES: Go to step 10CA12.

NO: Repair power supply line.

NOTE: In this case, repair the following:
- Open circuit in harness between main relay and front oxygen (A/F) sensor connector
- Poor contact in front oxygen (A/F) sensor connector
- Poor contact in main relay connector

10CA12: CHECK FRONT OXYGEN (A/F) SENSOR.

1. Turn ignition switch to OFF.

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





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

CHECK: Is the resistance less than 10 Ohms?

YES: Repair harness and connector.

NOTE: In this case, repair the following:
- Open or ground short circuit in harness between front oxygen (A/F) sensor and ECM connector
- Poor contact in front oxygen (A/F) sensor connector
- Poor contact in ECM connector

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