GM Service Manual Online
For 1990-2009 cars only

Circuit Description


Object Number: 902518  Size: MF

The transaxle fluid temperature (TFT) sensor circuit monitors transaxle fluid temperature by using a thermistor-type sensor located in a transaxle pressure port near the pressure filter. Sensor resistance will increase as the temperature decreases, and decrease as the temperature increases. The PCM/TC supplies a 5 volt signal to circuit 586 and monitors the voltage on the internal signal line as it varies up and down with circuit resistance. The voltage value on the signal line is converted to a temperature value.

Conditions for Setting the DTC

DTC P0172 is set when the PCM/TC has detected the following conditions for longer than 30 seconds:

    • The engine coolant temperature is below 100°C (212°F).
    • The sensor reading is above 140°C (284°F).

Test Description

Numbered steps below refer to numbered steps on the chart.

    Important: High temperature equals low sensor resistance.

  1. This step verifies the problem is still present. If the scan tool indicates the temperature is less than 140°C (248°F), the condition for DTC P0712 are not currently present.
  2. This step stimulates a DTC P0713. If the PCM recognizes the high signal, low temperature, and the scan tool reads less than -37°C (-35°F), the PCM and wiring are OK. With the ignition ON, 5 volts at the sensor harness terminal for circuit 586 indicates the PCM and circuit 586 are OK.

Repair Verification

Monitor the DTC menu Code Status for Pass Since Code Clear and Pass This Ignition Cycle. When both have passed, the repair is verified.

Criteria for pass:

    • Same as fail criteria
    • Criteria OK for 100 seconds

Diagnostic Aids

DTC P0712 is not set when the transaxle is overheated. That would cause DTC P0218 to set.


Object Number: 902554  Size: FP