A/T

DTC P0136 - REAR OXYGEN SENSOR CIRCUIT MALFUNCTION

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

11P1: CHECK ANY OTHER DTC ON DISPLAY.

CHECK: Does the Subaru Select Monitor or OBD-II general scan tool indicate DTC P1130 or P1131?

YES: Go to step 11P2.

NO: Go to step 11P3.

11P2: CHECK FAILURE CAUSE OF P0130

Inspect DTC P1130 or P1131 using "11.Diagnostics Chart with Trouble Code for AT Vehicles".

CHECK: Is the failure cause of P1130 or P1131 in the fuel system?

YES: Check fuel system.

NOTE: In this case, it is not necessary to inspect DTC P0136.

NO: Go to step 11P3.

11P3: CHECK REAR OXYGEN SENSOR DATA.

1. Warm-up the engine until engine coolant temperature is above 70 °C (160 °F), and keep the engine speed at 2,000 rpm to 3,000 rpm for two minutes.
2. Read data of rear oxygen sensor signal 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 general scan tool
For detailed operation procedures, refer to the OBD-II General Scan Tool Instruction Manual.

CHECK: Does the value fluctuate?

YES: Go to step 11P.

NO: Go to step 11P4.

11P4: CHECK REAR OXYGEN SENSOR DATA.
Read data of rear oxygen sensor signal using Subaru Select Monitor or OBD-II General Scan Tool.

CHECK: Is the value fixed between 0.2 and 0.4 V?

YES: Go to step 11P5.

NO: Replace rear oxygen sensor.

11P5: CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR CONNECTOR.

1. Turn ignition switch to OFF. 2. Disconnect connectors from ECM and rear oxygen sensor.

Connector & Terminal - [(B136) No.16 - (T6) No.3]:

3. Measure resistance of harness between ECM and rear oxygen sensor connector.

CHECK: Is the resistance more than 3 Ohms?

YES: Repair open circuit in harness between ECM and rear oxygen sensor connector.

NO: Go to step 11P6.

11P6: CHECK HARNESS BETWEEN REAR OXYGEN SENSOR AND ECM CONNECTOR.

1. Turn ignition switch to OFF.
2. Disconnect connector from rear oxygen sensor.
3. Turn ignition switch to ON.

Connector & Terminal - [(T6) No.4 (+) - Engine Ground (-)]:

4. Measure voltage between rear oxygen sensor harness connector and engine ground or chassis ground.

CHECK: Is the voltage more than 0.2 V?

YES: Replace rear oxygen sensor.

NO: Repair harness and connector.

NOTE: In this case, repair the following:
- Open circuit in harness between rear oxygen sensor and ECM connector
- Poor contact in rear oxygen sensor connector
- Poor contact in ECM connector

11P7: CHECK EXHAUST SYSTEM.
Check exhaust system parts.

NOTE: Check the following items.
- Loose installation of portions
- Damage (crack, hole etc.) of parts
- Looseness and ill fitting of parts between front oxygen (A/F) sensor and rear oxygen sensor

CHECK: Is there a fault in exhaust system?

YES: Repair or replace faulty parts.

NO: Replace rear oxygen sensor.