DTC P0768 Shift Solenoid "D" Electrical

WARNING: This page is about a different variant/trim than selected.

DTC DETECTING CONDITION:

The output signal circuit of low & reverse duty solenoid is open or shorted.

TROUBLE SYMPTOM:

Gear is not changed.

WIRING DIAGRAM:

Fig 1: Wiring Diagram - Shift Solenoid "D" Electrical

Courtesy of SUBARU OF AMERICA, INC.

DTC P0768 DIAGNOSTIC PROCEDURE

Step	CHECK	Yes	No
1 CHECK HARNESS CONNECTOR BETWEEN TCM AND TRANSMISSION. Turn the ignition switch to OFF. Disconnect the connector from transmission and TCM. Measure the resistance of harness between TCM and transmission connector. Connector & terminal (B55) No. 7 - (B11) No. 6:	Is the resistance less than 1 Ω?	Go to step 2 .	Repair the open circuit in 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 (B55) No. 7 - Chassis ground:	Is the resistance more than 1 MΩ?	Go to step 3 .	Repair the short circuit in 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 EMITTED FROM TCM USING SUBARU SELECT MONITOR. Connect all the connectors. Connect the Subaru Select Monitor to data link connector. Start the engine, and turn the Subaru Select Monitor switch to ON. Warm-up the transmission until the ATF temperature is above approx. 80°C (176°F). NOTE: If the ambient temperature is below 0°C (32°F), drive the vehicle until the ATF reaches its operating temperature. Stop the engine and turn the ignition switch to ON (engine OFF). Shift the select lever to the "N" range. Read the data of "L&R B duty ratio" using Subaru Select Monitor. Low & reverse duty solenoid is indicated in "%".	Is the value 100%?	Go to step 5 .	Go to step 6 .
5 CHECK OUTPUT SIGNAL EMITTED FROM TCM USING SUBARU SELECT MONITOR. Lift-up the vehicle and support with rigid racks. NOTE: Raise all wheels off floor. 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. NOTE: The speed difference between front and rear wheels may light the ABS warning light, but this indicates no malfunction. When AT control diagnosis is finished, perform the ABS memory clearance procedure of on-board diagnostics system. < Ref. to CLEAR MEMORY MODE . > Read the data of "L&R B duty ratio".	Is the value 55%?	Even if the SPORT indicator light is blinking, the circuit has returned to normal condition at this time. A temporary poor contact of connector or harness may be the cause. Repair the harness or connector in TCM and transmission.	Go to step 6 .
6 CHECK POOR CONTACT.	Is there poor contact in low & reverse duty solenoid circuit?	Repair the poor contact.	Replace the TCM. < Ref. to TRANSMISSION CONTROL MODULE (TCM) . >
7 CHECK LOW & REVERSE DUTY SOLENOID (IN TRANSMISSION). Remove the transmission connector from bracket. Drain the ATF. CAUTION: Do not drain the ATF until it cools down. Remove the oil pan, and disconnect the connector from control valve body. Measure the resistance between low & reverse duty solenoid connector and transmission ground. Connector & terminal (AT3) No. 1 - Transmission ground:	Is the resistance 2.0 - 6.0 Ω?	Go to step 8 .	Replace the control valve body. < Ref. to CONTROL VALVE BODY . >
8 CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND LOW & REVERSE DUTY SOLENOID. Measure the resistance of harness between low & reverse duty solenoid and transmission connector. Connector & terminal (T4) No. 6 - (AT3) No. 1:	Is the resistance less than 1 Ω?	Go to step 9 .	Repair the open circuit in harness between low & reverse duty solenoid and transmission connector.
9 CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND LOW & REVERSE DUTY SOLENOID. Measure the resistance of harness between transmission connector and transmission ground. Connector & terminal (T4) No. 6 - Transmission ground:	Is the resistance more than 1 MΩ?	Even if the SPORT indicator light is blinking, the circuit has returned to normal condition at this time. A temporary poor contact of connector or harness may be the cause. Repair the harness or connector in low & reverse duty solenoid and transmission.	Repair the short circuit in harness between low & reverse brake solenoid and transmission connector.