AUTOMATIC TRANSMISSION (DIAGNOSTICS)(4AT)(D) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC P0753 SHIFT SOLENOID “A” ELECTRICAL

DTC DETECTING CONDITION:

Output signal circuit of low clutch duty solenoid is open or shorted.

TROUBLE SYMPTOM:

Excessive shift shock

WIRING DIAGRAM:

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1.CHECK HARNESS CONNECTOR BETWEEN TCM AND TRANSMISSION.

1) Turn the ignition switch to OFF.

2) Disconnect the connectors from TCM and transmission.

3) Measure the resistance of harness between TCM and transmission connector.

Connector & terminal

(B54) No. 7 — (B11) No. 4:

Is the resistance less than 1 Ω?

Repair the open circuit of harness between TCM and transmission connector.

2.CHECK HARNESS CONNECTOR BETWEEN TCM AND TRANSMISSION.

Measure the resistance of harness between TCM connector and transmission ground.

Connector & terminal

(B54) No. 7 — Chassis ground:

Is the resistance 1 MΩ or more?

Repair the short circuit of harness between TCM and transmission connector.

3.CHECK LOW CLUTCH DUTY SOLENOID.

Measure the resistance between transmission connector terminals.

Connector & terminal

(T4) No. 4 — No. 20:

Is the resistance between 2.0 — 4.5 Ω?

4.CHECK OUTPUT SIGNAL FROM TCM USING SUBARU SELECT MONITOR.

1) Connect the connectors to TCM and transmission.

2) Connect the Subaru Select Monitor to the data link connector.

3) Start the engine, and turn the Subaru Select Monitor power switch to ON.

4) Warm-up the transmission until the ATF temperature exceeds approximately 80°C (176°F).

NOTE:

If the ambient temperature falls below 0°C (32°F), drive the vehicle until the ATF reaches its operating temperature.

5) Stop the engine and turn the ignition switch to ON (with engine OFF).

6) Shift the select lever to “P” or “N” range, and depress the accelerator pedal.

7) Read the data of low clutch duty solenoid using Subaru Select Monitor.

Low clutch duty solenoid is indicated in “%”.

Is the measured value 100%?

5.CHECK OUTPUT SIGNAL FROM TCM USING SUBARU SELECT MONITOR.

1) Turn the ignition switch to ON (engine OFF).

2) Move the select lever to “D” range.

3) Read the data of low clutch duty solenoid.

Is the measured value 0%?

Even if the power indicator light is blinking, the circuit is in normal condition at this time. A temporary poor contact of connector or harness may be the cause. Repair the harness or connector in transmission.

6.CHECK POOR CONTACT.

Is there poor contact in low clutch duty solenoid circuit?

Repair the poor contact.

Replace the TCM.

7.CHECK LOW CLUTCH DUTY SOLENOID (IN TRANSMISSION).

1) Remove the transmission connector from bracket.

2) Drain the automatic transmission fluid.

CAUTION:

Do not drain ATF until it cools down.

3) Remove the oil pan, and disconnect the connector from low clutch duty solenoid.

4) Measure the resistance between low clutch duty solenoid connector and transmission ground.

Connector & terminal

(AT12) No. 2 — Transmission ground:

Is the resistance between 2.0 — 4.5 Ω?

Replace the control valve body.

8.CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND LOW CLUTCH DUTY SOLENOID.

Measure the resistance of harness between low clutch duty solenoid and transmission connector.

Connector & terminal

(T4) No. 4 — (AT12) No. 2:

Is the resistance less than 1 Ω?

Repair the open circuit of harness between low clutch duty solenoid and transmission connector.

9.CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND LOW CLUTCH DUTY SOLENOID.

Measure the resistance of harness between transmission connector and transmission ground.

Connector & terminal

(T4) No. 4 — Transmission ground:

Is the resistance 1 MΩ or more?

Even if the power indicator light is blinking, the circuit is in normal condition at this time. A temporary poor contact of connector or harness may be the cause. Repair the harness or connector of the low clutch duty solenoid and transmission.

Repair the short circuit of harness between low clutch duty solenoid and transmission connector.