P1121
DTC P1121 - NEUTRAL POSITION SWITCH CIRCUIT HIGH INPUT [MT VEHICLES] OR NEUTRAL POSITION SWITCH CIRCUIT LOW INPUT [AT VEHICLES]DTC DETECTING CONDITION:
- Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
- Erroneous idling
CAUTION: After repair or replacement of faulty parts, conduct CLEAR MEMORY MODE and INSPECTION MODE. Refer to How to Clear Diagnostic Trouble Codes. Clear Memory Mode
WIRING DIAGRAM
10BV1: CHECK TRANSMISSION TYPE.
CHECK: Is transmission type MT?
YES: Go to step 10BV2.
NO: Go to step 10BV9.
10BV2: CHECK INPUT SIGNAL FOR ECM.
1. Turn ignition switch to ON.
Connector & Terminal (B135) No.26 (+) - Chassis Ground (-):
2. Measure voltage between ECM and chassis ground.
CHECK: Is the voltage more than 10 V in neutral position?
YES: Go to step 10BV3.
NO: Go to step 10BV5.
10BV3: CHECK INPUT SIGNAL FOR ECM.
Connector & Terminal (B135) No.26 (+) - Chassis Ground (-):
Measure voltage between ECM and chassis ground.
CHECK: Is the voltage less than 1 V in other positions?
YES: Go to step 10BV4.
NO: Go to step 10BV6.
10BV4: CHECK POOR CONTACT.
Check poor contact in ECM connector.
CHECK: Is there poor contact in ECM connector?
YES: Repair poor contact in ECM connector.
NO: Contact with Subaru of America (SOA) service.
NOTE: Inspection by Subaru of America's DTM is required, because probable cause is deterioration of multiple parts.
10BV5: CHECK NEUTRAL POSITION SWITCH.
Connector & Terminal (T2) No.1 - No.2:
Measure resistance between transmission harness connector terminals.
CHECK: Is the resistance less than 1 ohm in other positions?
YES: Go to step 10BV6.
NO: Repair open circuit in transmission harness or replace neutral position switch.
10BV6: CHECK HARNESS BETWEEN ECM AND NEUTRAL POSITION SWITCH CONNECTOR.
1. Disconnect connector from ECM.
Connector & Terminal (B135) No.26 - (B25) No.1:
2. Measure resistance of harness between ECM and transmission harness connector.
CHECK: Is the resistance less than 1 ohm?
YES: Go to step 10BV7.
NO: Repair open circuit in harness between ECM and transmission harness connector.
10BV7: CHECK HARNESS BETWEEN ECM AND NEUTRAL POSITION SWITCH CONNECTOR.
Connector & Terminal (B25) No.2 - Engine Ground:
Measure resistance of harness between transmission harness connector and engine ground.
CHECK: Is the resistance less than 5 ohm?
YES: Go to step 10BV8.
NO: Repair harness and connector.
NOTE:
In this case, repair the following:
- Open circuit in harness between transmission harness connector and engine grounding terminal
- Poor contact in coupling connector (B22)
10BV8: CHECK POOR CONTACT.
Check poor contact in transmission harness connector.
CHECK: Is there poor contact in transmission harness connector?
YES: Repair poor contact in transmission harness connector.
NO: Contact with Subaru of America (SOA) service.
NOTE: Inspection by Subaru of America's DTM is required, because probable cause is deterioration of multiple parts.
10BV9: CHECK DTC P0705 ON DISPLAY.
CHECK: Does the Subaru Select Monitor or OBD-II general scan tool indicate DTC P0705?
YES: Inspect DTC P0705 using "10. Diagnostics Chart with Trouble Code". P0705
NO: Go to step 10BV10.
10BV10: CHECK INPUT SIGNAL FOR ECM.
1. Turn ignition switch to ON.
Connector & Terminal (B135) No.26 (+) - Chassis Ground (-):
2. Measure voltage between ECM and chassis ground.
CHECK: Is the voltage between 4.5 and 5.5 V at except "N" and "P" positions?
YES: Even if MIL lights up, the circuit has returned to a normal condition at this time.
NO: Go to step 10BV11.
10BV11: CHECK HARNESS BETWEEN ECM AND TRANSMISSION HARNESS CONNECTOR.
1. Turn ignition switch to OFF.
2. Disconnect connectors from ECM and transmission harness connector (T3).
Connector & Terminal (B135) No.26 - Chassis Ground:
3. 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 transmission harness connector.
NO: Go to step 10BV12.
10BV12: CHECK TRANSMISSION HARNESS CONNECTOR.
1. Disconnect connector from inhibitor switch.
Connector & Terminal (T3) No.12 - Engine Ground:
2. Measure resistance of harness between transmission harness connector and engine ground.
CHECK: Is the resistance less than 10 ohm?
YES: Repair ground short circuit in harness between transmission harness and inhibitor switch connector.
NO: Go to step 10BV13.
10BV13: CHECK INHIBITOR SWITCH.
Terminals No.7 - No.12:
Measure resistance between inhibitor switch connector receptacle's terminals in selector lever except for "N" position.
CHECK: Is the resistance more than 1 Mohm at except "N" and "P" positions?
YES: Go to step 10BV14.
NO: Replace inhibitor switch.
10BV14: CHECK SELECTOR CABLE CONNECTION.
CHECK: Is there any fault in selector cable connection to inhibitor switch?
YES: Repair selector cable connection.
NO: Contact with Subaru of America (SOA) service.
NOTE: Inspection by Subaru of America's DTM is required, because probable cause is deterioration of multiple parts.