DTC 74 2-4 Brake Timing Solenoid

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

DIAGNOSIS:

The output signal circuit of 2-4 brake timing solenoid is open or shorted.

TROUBLE SYMPTOM:

Excessive shift shock.

WIRING DIAGRAM:

Fig 1: 2-4 Brake Timing Solenoid - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE CHART

Step	Check	Yes	No
1 CHECK HARNESS CONNECTOR BETWEEN TCM AND TRANSMISSION. Turn the ignition switch to OFF. Disconnect the connector from TCM and transmission. Measure the resistance of harness between TCM and transmission connector. Connector & terminal (B54) No. 5 - (B11) No. 4:	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 TRANSMISSION. Measure the resistance of harness between TCM connector and chassis ground. Connector & terminal (B54) No. 5 - 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 2-4 BRAKE TIMING SOLENOID. Measure the resistance between transmission connector terminals. Connector & terminal (T4) No. 4 - No. 16:	Is the resistance 10 - 16 Ω?	Go to step 4.	Go to step 7.
4 CHECK OUTPUT SIGNAL EMITTED FROM TCM. Connect the connectors to TCM and transmission. Lift-up or raise the vehicle and support with safety stand. NOTE: Raise all wheels off ground. 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. Move the selector lever to "1" range, and slowly increase vehicle speed to 10 km/h (6 MPH). 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 . > Measure the voltage between TCM connector and chassis ground. Connector & terminal (B54) No. 5 (+) - Chassis ground (-):	Is the voltage less than 1 V?	Go to step 5.	Go to step 6.
5 CHECK OUTPUT SIGNAL EMITTED FROM TCM. Move the selector lever to "D" range, and slowly increase vehicle speed to 65 km/h (40 MPH). 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 . > Measure the voltage between TCM connector and chassis ground. Connector & terminal (B54) No. 5 (+) - Chassis ground (-):	Is the voltage more than 9 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 contact in transmission.	Go to step 6.
6 CHECK POOR CONTACT.	Is there poor contact in 2-4 brake timing solenoid circuit?	Repair the poor contact.	Replace the TCM. < Ref. to TRANSMISSION CONTROL MODULE (TCM) . >
7 CHECK 2-4 BRAKE TIMING SOLENOID (IN TRANSMISSION). Remove the transmission connector from bracket. Lift-up or raise the vehicle and support with safety stand. NOTE: Raise all wheels off ground. Drain the ATF. CAUTION: Do not drain the ATF until it cools down. Remove the oil pan, and disconnect connector from 2-4 brake timing solenoid. Measure the resistance between 2-4 brake timing solenoid connector and transmission ground. Terminals No. 1 - Transmission ground:	Is the resistance 10 - 16 Ω?	Go to step 8.	Replace the 2-4 brake timing solenoid. < Ref. to SHIFT SOLENOIDS, DUTY SOLENOIDS AND ATF TEMPERATURE SENSOR . >
8 CHECK HARNESS CONNECTOR BETWEEN 2-4 BRAKE TIMING SOLENOID AND TRANSMISSION. Measure the resistance of harness between 2-4 brake timing solenoid and transmission connector. Connector & terminal (AT8) No.1 - (T4) No. 4:	Is the resistance less than 1 Ω?	Go to step 9.	Repair the open circuit in harness between 2-4 brake timing solenoid and transmission connector.
9 CHECK HARNESS CONNECTOR BETWEEN 2-4 BRAKE TIMING SOLENOID AND TRANSMISSION. Measure the resistance of harness between 2-4 brake timing solenoid connector and transmission ground. Connector & terminal (T4) No. 4 - 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 2-4 brake timing solenoid and transmission.	Repair the short circuit harness between 2-4 brake timing solenoid and transmission connector.