DTC 75 Line Pressure Duty Solenoid

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

DIAGNOSIS:

Output signal circuit of line pressure duty solenoid is open or shorted.

TROUBLE SYMPTOM:

Excessive shift shock.

WIRING DIAGRAM:

Fig 1: Line Pressure Duty Solenoid - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE CHART

Step	Check	Yes	No
1 CHECK RESISTOR. Turn the ignition switch to OFF. Disconnect the connector from dropping resistor. Measure the resistance between dropping resistor terminal. Terminals No. 1 - No. 2:	Is the resistance 9 - 15 Ω?	Go to step 2.	Replace the dropping resistor. < Ref. to DROPPING RESISTOR . >
2 CHECK HARNESS CONNECTOR BETWEEN TCM AND DROPPING RESISTOR. Disconnect the connector from TCM. Measure the resistance of harness between TCM connector and dropping resistor connector. Connector & terminal (B54) No. 18 - (B4) No. 1:	Is the resistance less than 1 Ω?	Go to step 3.	Repair open circuit in harness between TCM and dropping resistor connector.
3 CHECK HARNESS CONNECTOR BETWEEN TCM AND DROPPING RESISTOR. Measure the resistance of harness between dropping resistor connector and chassis ground. Connector & terminal (B4) No. 1 - Chassis ground:	Is the resistance more than 1 MΩ?	Go to step 4.	Repair short circuit in harness between TCM and dropping resistor connector.
4 CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND DROPPING RESISTOR. Disconnect the connector from transmission. Measure the resistance of harness between transmission and dropping resistor connector. Connector & terminal (B4) No. 2 - (B11) No. 5:	Is the resistance less than 1 Ω?	Go to step 5.	Repair open circuit in harness between dropping resistor and transmission connector.
5 CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND DROPPING RESISTOR. Measure the resistance of harness between dropping resistor connector and chassis ground. Connector & terminal (B4) No. 2 - Chassis ground:	Is the resistance more than 1 MΩ?	Go to step 6.	Repair short circuit in harness between dropping resistor and transmission connector.
6 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 (B54) No. 9 - (B11) No. 5:	Is the resistance less than 1 Ω?	Go to step 7.	Repair the open circuit in harness between TCM and transmission connector.
7 CHECK HARNESS CONNECTOR BETWEEN TCM AND CHASSIS GROUND. Measure the resistance of harness between TCM and chassis ground. Connector & terminal (B54) No. 9 - Chassis ground:	Is the resistance more than 1 MΩ?	Go to step 8.	Repair the short circuit in harness between TCM and transmission connector.
8 CHECK LINE PRESSURE DUTY SOLENOID. Measure the resistance between transmission connector receptacle's terminals. Terminals (T4) No. 5 - No. 16:	Is the resistance 2.0 - 4.5 Ω?	Go to step 9.	Go to step 15.
9 PREPARE SUBARU SELECT MONITOR.	Do you have a Subaru Select Monitor?	Go to step 12.	Go to step 10.
10 CHECK OUTPUT SIGNAL EMITTED FROM TCM. Connect all connectors. Start the engine and warm-up the transmission until ATF temperature is above 80°C (176°F). NOTE: If ambient temperature is below 0°C (32°F), drive the vehicle until ATF reaches its operating temperature. Turn the ignition switch to ON (engine OFF). Move the select lever to "N" range. Throttle fully closed. Measure the voltage between TCM connector and chassis ground. Connector & terminal (B54) No. 9 (+) - Chassis ground (-):	Is the voltage 1.5 - 5.0 V?	Go to step 11.	Go to step 14.
11 CHECK OUTPUT SIGNAL EMITTED FROM TCM. Throttle fully open and hold it. Measure the voltage between TCM connector and chassis ground. Connector & terminal (B54) No. 9 (+) - Chassis ground (-):	Is the voltage less than 1 V?	Even if the AT OIL TEMP warning light blinks, the circuit has returned to a normal condition at this time. A temporary poor contact of the connector or harness may be the cause. Repair the harness or connector in transmission.	Go to step 14.
12 CHECK OUTPUT SIGNAL EMITTED FROM TCM USING SUBARU SELECT MONITOR. Connect the connectors to TCM and transmission. Connect the Subaru Select Monitor to data link connector. Start the engine and turn Subaru Select Monitor switch to ON. Warm-up the transmission until ATF temperature is above 80°C (176°F). NOTE: If ambient temperature is below 0°C (32°F), drive the vehicle until ATF reaches its operating temperature. Stop the engine and turn ignition switch to ON (engine OFF). Move the select lever to "N" range. Read the data of line pressure duty solenoid using Subaru Select Monitor. Line pressure duty solenoid is indicated in "%". Throttle is fully closed.	Is the value 100%?	Go to step 13.	Go to step 14.
13 CHECK OUTPUT SIGNAL EMITTED FROM TCM USING SUBARU SELECT MONITOR. Turn the ignition switch to ON (engine OFF). Throttle is fully open.	Is the value less than 25%?	Even if the AT OIL TEMP warning light blinks, the circuit has returned to a normal condition at this time. A temporary poor contact of the connector or harness may be the cause. Repair the harness or connector in transmission.	Go to step 14.
14 CHECK POOR CONTACT.	Is there poor contact in line pressure duty solenoid circuit?	Repair the poor contact.	Replace the TCM. < Ref. to TRANSMISSION CONTROL MODULE (TCM) . >
15 CHECK LINE PRESSURE 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 connector from line pressure duty solenoid. Measure the resistance between line pressure duty solenoid connector and transmission ground. Terminals No. 1 - Transmission ground:	Is the resistance 2.0 - 4.5 Ω?	Go to step 16.	Replace the line pressure duty solenoid. < Ref. to SHIFT SOLENOIDS, DUTY SOLENOIDS AND ATF TEMPERATURE SENSOR . >
16 CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND LINE PRESSURE DUTY SOLENOID. Measure the resistance of harness between line pressure duty solenoid and transmission connector. Connector & terminal (T4) No. 5 - (AT2) No. 1:	Is the resistance less than 1 Ω?	Go to step 17.	Repair the open circuit in harness between line pressure duty solenoid and transmission connector.
17 CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND LINE PRESSURE DUTY SOLENOID. Measure the resistance of harness between transmission connector and transmission ground. Connector & terminal (T4) No. 5 - Transmission ground:	Is the resistance more than 1 MΩ?	Even if the AT OIL TEMP warning light blinks, the circuit has returned to a normal condition at this time. A temporary poor contact of the connector or harness may be the cause. Repair the harness or connector in line pressure duty solenoid and transmission.	Repair the short circuit in harness between line pressure duty solenoid and transmission connector.