P0712

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The Transmission Fluid Temperature (TFT) sensor contains a semiconductor device which changes resistance based on temperature (a thermistor). The TFT sensor is located inside the transmission on the adapter case valve body. The TFT sensor has a signal circuit and a ground circuit. The Transmission Control Module (TCM) applies a voltage (about 5.0 volts) on the signal circuit to the sensor. The TCM monitors the changes in this voltage which cause changes in the resistance of the sensor to determine transmission fluid temperature.

When the fluid is cold, the sensor (thermistor) resistance is high, and the TCM's signal voltage drops a small amount through the sensor to ground. Therefore, the TCM will sense a high signal voltage (low temperature). When the fluid is warm, the sensor resistance is low, and the signal voltage drops a greater amount. This drop causes the TCM to sense a low signal voltage (high temperature). When the TCM senses a signal voltage lower than the normal operating range of the sensor, this DTC will set.

CONDITIONS FOR RUNNING THE DTC

Tests continuously

CONDITIONS FOR SETTING THE DTC

The TFT is less than 59 mV

Condition present for 20 seconds

ACTION TAKEN WHEN THE DTC SETS

^ The Malfunction Indicator Lamp (MIL)/Service Transmission Lamp (STL) will not illuminate.

^ The TCM memory stores the DTC at the time of the first failure.

CONDITIONS FOR CLEARING THE MIL/DTC

^ A History DTC clears after forty consecutive warm-up cycles if no failures are present by this or any other non-emission related diagnostic.

^ The scan tool clears the MIL/DTC.

DIAGNOSTIC AIDS

Use the Connector Test Adapter Kit J 35616-A for any test that requires probing the TCM harness connector or a component harness connector. Using this kit will prevent damage to the harness connector terminals.

Check for the following conditions:

^ Poor connections at the TCM or at the component. Inspect the harness connectors for any backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. Refer to Overall Vehicle Information / Diagrams / Diagnostic Aids for Checking Terminal Contact procedure.

^ Damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, observe the scan tool while moving any related connectors and any wiring harnesses. A change in the display may help to locate the fault.