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DTC 27 ATF TEMPERATURE SENSOR

DTC 27 ATF TEMPERATURE SENSOR

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

(B54) No. 20 — (B11) No. 12:

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

(B54) No. 11 — (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 connector and chassis ground.

Connector & terminal

(B54) No. 20 — Chassis ground:

Is the resistance more than 1 MΩ?

Yes


No

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


CHECK HARNESS CONNECTOR BETWEEN TCM AND ATF TEMPERATURE SENSOR.

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

Connector & terminal

(B54) No. 11 — Chassis ground:

Is the resistance more than 1 MΩ?

Yes


No

Repair the short 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. 12:

Is the resistance 275 — 375 Ω?

Yes


No

Replace the ATF temperature sensor.


CHECK ATF TEMPERATURE SENSOR.

Turn the ignition switch to ON (engine OFF).

Measure the resistance between transmission connector terminals.

Connector & terminal

(T4) No. 11 — No. 12:

Does the resistance value increase while ATF temperature decreases?

Yes


No

Replace the ATF temperature sensor.


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 AT OIL TEMP warning light 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 poor 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.