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.
- Turn ignition switch to OFF.
- Disconnect connectors from TCM and ECM.




- Measure resistance of harness connector between TCM and ECM.

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




- 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 Ohm, or more

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



- Measure signal voltage between TCM connector terminal and body.

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

TROUBLESHOOTING WITH A SUBARU SELECT MONITOR
- Connect connectors to TCM and ECM.
- Turn ignition switch to OFF.



- Connect the Subaru Select Monitor to data link connector.
- Turn ignition switch to ON and Subaru Select Monitor switch to ON.
- Start the engine (engine idling after warm-up).



- Read data on Subaru Select Monitor.
- Designate mode using function key.

Function mode: F15
SPECIFIED DATA: 0.5 - 1.22 Volts (Engine warm-up)