MT Model

DTC detecting condition:

Detected when two consecutive driving cycles with fault occur.

Trouble symptom:

Improper idling

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE>OPERATION , and inspection mode Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>INSPECTION MODE>PROCEDURE ..
Use the check board when measuring the ECM terminal voltage and resistance.

Wiring diagram:

Engine Electrical System Refer to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CHECK INPUT SIGNAL OF ECM.
1. Turn the ignition switch to ON.
2. Place the gear shift lever in neutral.
3. Measure the voltage between ECM connector and engine ground.
  Connector & terminal
  
  (B134) No. 33 (+) - Engine ground (-):
Is the voltage less than 1 V?

Yes: Repair the poor contact of ECM connector.

No: Go to 2.
CHECK HARNESS BETWEEN ECM AND NEUTRAL POSITION SWITCH CONNECTOR.
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connector from the neutral position switch.
4. Measure the resistance of harness between ECM connector and neutral position switch connector.
  Connector & terminal
  
  (B134) No. 33 - (B25) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 3.

No: Repair the open circuit in harness between ECM connector and transmission harness connector.
CHECK HARNESS BETWEEN NEUTRAL POSITION SWITCH CONNECTOR AND CHASSIS GROUND.
Measure the resistance of harness between neutral position switch connector and chassis ground.

Connector & terminal

(B25) No. 1 - Chassis ground:

Is the resistance less than 5 Ω?

Yes: Go to 4.

No: Repair the harness and connector.
NOTE:
In this case, repair the following item:
- Open circuit in harness between neutral position switch connector and chassis ground
- Poor contact of coupling connector
CHECK NEUTRAL POSITION SWITCH.
1. Place the gear shift lever in neutral.
2. Measure the resistance between neutral position switch connector terminals.
  Connector & terminal
  
  (T2) No. 1 - (T2) No. 2:
Is the resistance less than 1 Ω?

Yes: Repair the poor contact of neutral position switch connector.

No: Replace the neutral position switch. Refer to MANUAL TRANSMISSION AND DIFFERENTIAL (6MT) (TY75)>SWITCHES AND HARNESS .