P0136
DTC P0136 - REAR OXYGEN SENSOR CIRCUIT MALFUNCTIONDTC 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
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 2500 cc Models".
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 11P7.
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 Volt?
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 - (E25) 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 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 (E25) 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 Volt?
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.