Diagnostic Procedure

WARNING: This page is about a different car, the 2013 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK HARNESS CONNECTOR BETWEEN TCM AND TRANSMISSION. Turn the ignition switch to OFF. Disconnect the connectors from TCM and transmission. Measure the resistance of harness between TCM connector and transmission connector. Connector & terminal (B54) No. 5 - (B11) No. 6:	Is the resistance less than 1 Ω?	Go to step 2 .	Repair the open circuit of harness between TCM and transmission connector.
2 CHECK HARNESS CONNECTOR BETWEEN TCM AND CHASSIS GROUND. Measure the resistance of harness between TCM connector and chassis ground. Connector & terminal (B54) No. 5 - Chassis ground:	Is the resistance 1 MΩ or more?	Go to step 3 .	Repair the short circuit of harness between TCM and transmission connector.
3 CHECK LOW & REVERSE DUTY SOLENOID. Measure the resistance between transmission connector terminals. Connector & terminal (T4) No. 6 - No. 20:	Is the resistance 2.0 - 6.0 Ω?	Go to step 4 .	Go to step 7 .
4 CHECK OUTPUT SIGNAL OF TCM. Connect all connectors. Connect the Subaru Select Monitor to data link connector. Start the engine. Run the Subaru Select Monitor. Warm up the transmission until the ATF temperature exceeds approximately 80°C (176°F). Stop the engine. Turn the ignition switch to ON. Set the select lever to "N" range. Read the data of «L&R B Duty» using Subaru Select Monitor.	Is the measured value 100%?	Go to step 5 .	Go to step 6 .
5 CHECK OUTPUT SIGNAL OF TCM. Lift up the vehicle. Shift the select lever to manual mode, and then hold it on 1st. Slowly increase the vehicle speed up to 15 km/h (9 MPH), and then return the accelerator pedal. Read the data of «L&R B Duty» using Subaru Select Monitor. NOTE: The speed difference between the front and rear wheels will illuminate the ABS warning light or VDC warning light, but this does not indicate a malfunction. If the warning light illuminates, delete the ABS or VDC memory of the on-board diagnosis system after completing the AT control diagnosis. < Refer to CLEAR MEMORY MODE . >	Is the measured value 55%?	Check the harnesses or connectors between TCM and transmission, and repair the defective part.	Go to step 6 .
6 CHECK FOR POOR CONTACT.	Is there poor contact of the low & reverse duty solenoid circuit?	Repair the poor contact.	Replace the TCM. < Refer to TRANSMISSION CONTROL MODULE (TCM) . >
7 CHECK LOW & REVERSE BRAKE DUTY SOLENOID (IN TRANSMISSION). Remove the transmission connector from bracket. Drain the automatic transmission fluid. CAUTION: Do not drain ATF until it cools down. Remove the oil pan. Disconnect the connector from the control valve body. Measure the resistance between low & reverse duty solenoid connector and transmission ground. Connector & terminal (AT2) No. 1 - Transmission ground:	Is the resistance 2.0 - 6.0 Ω?	Go to step 8 .	Replace the control valve body. < Refer to CONTROL VALVE BODY . >
8 CHECK HARNESS CONNECTOR BETWEEN LOW & REVERSE DUTY SOLENOID AND TRANSMISSION. Measure the resistance of harness between low & reverse duty solenoid and transmission connector. Connector & terminal (T4) No. 6 - (AT2) No. 1:	Is the resistance less than 1 Ω?	Go to step 9 .	Repair open circuit of harness between low & reverse duty solenoid and transmission connector.
9 CHECK HARNESS CONNECTOR BETWEEN LOW & REVERSE DUTY SOLENOID AND TRANSMISSION. Measure the resistance of harness between transmission connector and transmission ground. Connector & terminal (T4) No. 6 - Transmission ground:	Is the resistance 1 MΩ or more?	Check the harnesses or connectors between low & reverse duty solenoid and transmission, and repair the defective part.	Repair the short circuit of the harness between the low & reverse duty solenoid and the transmission connector.