M/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

10Q1: 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 10Q2.

NO: Go to step 10Q3.

10Q2: CHECK FAILURE CAUSE OF P1130 OR P1131.
Inspect DTC P1130 or P1131 using "10. Diagnostics Chart with Trouble Code for MT 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 10Q3.

10Q3: CHECK REAR OXYGEN SENSOR DATA.

1. Start the engine.
2. 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.
3. 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 10Q7.

NO: Go to step 10Q4.

10Q4: 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 10Q5.

NO: Replace rear oxygen sensor.

10Q5: 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 Ohm ?

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

NO: Go to step 10Q6.

10Q6: CHECK HARNESS BETWEEN REAR OXYGEN SENSOR AND ECM CONNECTOR.

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

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

3. 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

10Q7: 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.