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DTC P0768 SHIFT SOLENOID “D” ELECTRICAL

DTC P0768 SHIFT SOLENOID “D” ELECTRICAL

DIAGNOSIS:

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

TROUBLE SYMPTOM:

Gear is not changed.

WIRING DIAGRAM:


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

(B56) No. 7 — (B11) No. 6:

Is the resistance less than 1 Ω?

Yes


No

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


CHECK HARNESS CONNECTOR BETWEEN TCM AND CHASSIS GROUND.

Measure the resistance of harness between TCM and chassis ground.

Connector & terminal

(B56) No. 7 — Chassis ground:

Is the resistance more than 1 MΩ?

Yes


No

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


CHECK LOW & REVERSE BRAKE DUTY SOLENOID.

Measure the resistance between transmission connector receptacle’s terminals.

Connector & terminal

(T4) No. 6 — No. 20:

Is the resistance 2.0 — 6.0 Ω?

Yes


No


CHECK OUTPUT SIGNAL FROM TCM USING Vehicle Diagnostic Interface.

Connect all connectors.

Connect the Vehicle Diagnostic Interface to data link connector.

Start the engine and turn Vehicle Diagnostic Interface 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).

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

Read the data of low & reverse duty solenoid using Vehicle Diagnostic Interface.


• Low & reverse duty solenoid is indicated in “%”.


Is the value 100%?

Yes


No


CHECK OUTPUT SIGNAL FROM TCM USING Vehicle Diagnostic Interface.

Move the select lever to “1” range.

Read the data of low & reverse duty solenoid.

Is the value 55%?

Yes

Even if the POWER indicator 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 TCM and transmission.


No


CHECK POOR CONTACT.

Is there poor contact in low & reverse duty solenoid circuit?

Yes

Repair the poor contact.


No

Replace the TCM.


CHECK LOW & REVERSE BRAKE DUTY SOLENOID (IN TRANSMISSION).

Remove the transmission connector from bracket.

Drain the ATF.

Important

Do not drain the ATF until it cools down.


Remove the oil pan, and disconnect connector from low & reverse duty solenoid.

Measure the resistance between low & reverse duty solenoid connector and transmission ground.

Connector & terminal

(AT12) No. 1 — Transmission ground:

Is the resistance 2.0 — 6.0 Ω?

Yes


No

Replace the low & reverse brake duty solenoid.


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 — (AT12) No. 1:

Is the resistance less than 1 Ω?

Yes


No

Repair the open circuit in harness between low & reverse brake duty solenoid and transmission connector.


CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND LOW & REVERSE BRAKE 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?

Yes

Even if the POWER indicator 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 low & reverse brake duty solenoid and transmission.


No

Repair the short circuit in harness between low & reverse brake duty solenoid and transmission connector.