P0141
DTC P0141 - REAR OXYGEN SENSOR HEATER CIRCUIT LOW INPUTDTC 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
10S1: CHECK ANY OTHER DTC ON DISPLAY.
CHECK: Does the Subaru Select Monitor or OBD-II general scan tool indicate DTC P0141 and P0135 at the same time?
YES: Go to step 10S2.
NO: Go to step 10S3.
10S2: CHECK GROUND CIRCUIT OF ECM.
1. Turn ignition switch to OFF.
2. Disconnect connector from ECM.
Connector & terminal (B134) No.35- Chassis ground:
3. Measure resistance of harness between ECM connector and chassis ground.
CHECK: Is the resistance less than 10 ohm?
YES: Go to step 10S4.
NO: Go to step 10S3.
10S3: CHECK GROUND CIRCUIT OF ECM.
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)
Connector & terminal (B134) No.34 - Chassis ground:
2. Measure resistance of harness between ECM connector and chassis ground.
CHECK: Is the resistance less than 5 ohm?
YES: Go to step 10S4.
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)
10S4: CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR CONNECTOR.
Connector & terminal (B134) No.21 - Chassis ground:
Measure resistance of harness between ECM connector and chassis ground.
CHECK: Is the resistance less than 10 ohm?
YES: Repair ground short circuit in harness between ECM and rear oxygen sensor connector.
NO: Go to step 10S5.
10S5: CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR CONNECTOR.
1. Disconnect connector from rear oxygen sensor.
Connector & terminal (B134) No.21 - (E25) No.4:
2. Measure resistance of harness between ECM and rear oxygen sensor connector.
CHECK: Is the resistance less than 3 ohm?
YES: Go to step 10S6.
NO: Repair open circuit in harness between ECM and rear oxygen sensor connector.
10S6: CHECK POWER SUPPLY TO REAR OXYGEN SENSOR.
1. Connect connector to ECM.
2. Turn ignition switch to ON.
Connector & terminal (E25) No.2 (+) - Engine ground (-):
3. Measure voltage between rear oxygen sensor connector and engine ground or chassis ground.
CHECK: Is the voltage more than 10 Volt?
YES: Go to step 10S7.
NO: Repair power supply line.
NOTE: In this case, repair the following:
- Open circuit in harness between main relay and rear oxygen sensor connector
- Poor contact in rear oxygen sensor connector
- Poor contact in coupling connector (E1)
10S7: CHECK REAR OXYGEN SENSOR
1. Turn ignition switch to OFF.
Terminals No.2- No.4:
2. Measure resistance between rear oxygen sensor connector terminals.
CHECK: Is the resistance less than 30 ohm?
YES: 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
- Poor contact in coupling connector (E1)
NO: Replace rear oxygen sensor.