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DTC P0712 TRANSMISSION FLUID TEMPERATURE SENSOR CIRCUIT LOW INPUT

DTC P0712 TRANSMISSION FLUID TEMPERATURE SENSOR CIRCUIT LOW INPUT

DIAGNOSIS:

The input signal circuit of TCM to ATF temperature sensor is open or shorted.

TROUBLE SYMPTOM:

Excessive shift shock.

WIRING DIAGRAM:


CHECK HARNESS CONNECTOR BETWEEN TCM AND ATF TEMPERATURE SENSOR.

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. 21 — (B11) No. 11:

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 ATF TEMPERATURE SENSOR.

Measure the resistance of harness between TCM and transmission connector.

Connector & terminal

(B55) No. 9 — (B11) No. 15:

Is the resistance less than 1 Ω?

Yes


No

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


CHECK ATF TEMPERATURE SENSOR.

Turn the ignition switch to OFF.

Connect the connectors to transmission and TCM.

Turn the ignition switch to ON and start engine.

Warm-up the transmission until ATF temperature reaches to 80°C (176°F).

Note

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


Disconnect the connector from transmission.

Measure the resistance between transmission connector terminals.

Connector & terminal

(T4) No. 11 — No. 15:

Is the resistance 300 — 800 Ω?

Yes


No


CHECK ATF TEMPERATURE SENSOR.

Measure the resistance between transmission connector terminals.

Connector & terminal

(T4) No. 11 — No. 15:

Does the resistance value increase when ATF temperature decreases?

Yes


No


CHECK INPUT SIGNAL FOR TCM USING Vehicle Diagnostic Interface.

Connect the connector to transmission.

Turn the ignition switch to ON (engine OFF).

Does the ATF temperature gradually decrease?

Yes

Even if the POWER indicator blinks, the circuit has returned to a normal condition at this time. Temporary poor contact of the connector or harness may be the cause. Repair the harness or contact in ATF temperature sensor and transmission connector.


No


CHECK POOR CONTACT.

Is there poor contact in ATF temperature sensor circuit?

Yes

Repair the poor contact.


No

Replace the TCM.


CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND ATF TEMPERATURE SENSOR.

Turn the ignition switch to OFF.

Disconnect the connector from transmission.

Remove the transmission connector from bracket.

Lift-up the vehicle and place rigid racks.

Note

Raise all wheels off floor.


Drain the ATF.

Important

Do not drain the ATF until it cools down.


Remove the oil pan, and disconnect the connector from ATF temperature sensor connector.

Measure the resistance of harness between ATF temperature sensor and transmission connector.

Connector & terminal

(T4) No. 11 — (AT11) No. 1:

Is the resistance less than 1 Ω?

Yes


No

Repair the open circuit in harness between ATF temperature sensor and transmission connector.


CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND ATF TEMPERATURE SENSOR.

Measure the resistance of harness between ATF temperature sensor and transmission connector.

Connector & terminal

(T4) No. 15 — (AT11) No. 3:

Is the resistance less than 1 Ω?

Yes


No

Repair the open circuit in harness between ATF temperature sensor and transmission connector.


CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND ATF TEMPERATURE SENSOR.

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

Connector & terminal

(T4) No. 11 — Transmission ground:

Is the resistance more than 1 MΩ?

Yes


No

Repair the short circuit in harness between ATF temperature sensor and transmission connector.


CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND ATF TEMPERATURE SENSOR.

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

Connector & terminal

(T4) No. 15 — Transmission ground:

Is the resistance more than 1 MΩ?

Yes

Replace the ATF temperature sensor.


No

Repair the short circuit in harness between ATF temperature sensor and transmission connector.