P0712 - TRANSMISSION FLUID TEMPERATURE SENSOR 'A' CIRCUIT LOW INPUT INPUT

The Transmission Fluid Temperature (TFT) sensor produces an electrical signal that it sends to the Powertrain Control Module (PCM) to determine shift points, Torque Converter Clutch (TCC) control and line pressure. This sensor is usually found in the transmission oil pan.

The TFT sensor receives 5 volts of reference voltage from the PCM. It should be noted that the internal resistance of this sensor varies with transmission fluid temperature, and this is returned as a signal to the PCM.

If the DTC P0712 OBDII code is set, it is because the PCM has discovered a low signal on the TFT sensor and the Check Engine light will illuminate. This is usually due to a short in the circuit.

• MIL (Engine Malfunction) light on.
• Torque Converter Clutch operates incorrectly.
• Shift delays.

Factors that lead to the P0712 OBD2 fault code setting are:

• The Transmission Fluid Temperature Sensor may be malfunctioning.
• The transmission may be exhibiting problems.
• The wires that are related to this system may have defects.

To resolve the faults associated with the P0712 OBDII error code you must do the following:

• Inspect the TFT Sensor and its wiring. If there are misaligned connections or damaged wires you must make the necessary corrections.
• Unplug the Transmission Fluid Temperature Sensor connector and measure the resistance between the two terminals. Then start the engine and observe on the gauge if the values have decreased. Confirm if the engine temperature has increased. If the resistance has not decreased, the sensor should be replaced.
• Check the reference voltage of the circuit. To do this, you must have the ignition on and with a multimeter set to ohms check the 5 volt reference from the PCM at one of the sensor terminals. If no such voltage is present, connect the meter to the TFT Sensor reference voltage pin and the PCM reference voltage pin. If there is a reading outside the limits it is because the circuit between the PCM and the sensor is open. You should make the necessary repairs.
• Check the ground circuit between the PCM and the TFT Sensor for proper ground. Perform the appropriate measurements and if you determine that the circuit is open you should make repairs.