Transmission Control Systems

DIAGNOSIS:
Input signal circuit of TCM from ECM Is open or shorted.

TROUBLE SYMPTCM:
Excessive shift shock





WIRING DIAGRAM:





1. CHECK TROUBLE CODE ON ENGINE SIDE.
Using Subaru select monitor or OBD-II general scan tool, check trouble code of mass air flow sensor on engine side.

2. CHECK HARNESS CONNECTOR BETWEEN TCM AND ECM.
1) Turn ignition switch to OFF.
2) Disconnect connectors from TCM and ECM.





3) Measure resistance of harness connector between TCM and ECM.

Specified resistance (B67) No. 9 - (B59) No. 47: 1 ohms, or less





4) Measure resistance of harness connector between TCM and body to make sure that circuit does not short.

Specified resistance (B67) No. 9 - Body: 1 M Ohms, or more

3. CHECK INPUT SIGNAL FOR TCM.
1) Connect connectors to TCM and ECM.
2) Start the engine. (engine idling after warm-up)





3) Measure signal voltage between TCM connector terminal and body.

Specified voltage, Engine warm-up: (B67) No. 9 - Body: 0.5 - 1.22 V

- Using Subaru select monitor:
(1) Connect connectors to TCM and ECM.
(2) Turn ignition switch to OFF.





(3) Connect the Subaru select monitor to data link connector.
(4) Turn ignition switch to ON and Subaru select monitor switch to ON.
(5) Start the engine (engine idling after warm-up).





(6) Read data on Subaru select monitor.
(7) Designate mode using function key.

Function mode: F15

SPECIFIED DATA: 0.5 - 1.22 V (Engine warm-up)