P0712

DTC P0712 Fluid Temperature Sensor CKT Low Input (1 Of 2):

DTC P0712 Fluid Temperature Sensor CKT Low Input (2 Of 2):

Fluid Temperature Sensor CKT:

CIRCUIT DESCRIPTION

The Automatic Transmission Fluid Temperature (TFT) sensor is a negative coefficient thermistor. The sensor resistance changes with temperature. The Powertrain Control Module (PCM) provides a 5-volt reference to the sensor on circuit 1227. A short to ground in circuit 1227 results in low signal voltage. The TFT operating range is from -40 to +140°C (-40 to +284°F).

When the PCM detects a voltage input of less than 200 mV in the TFT Sensor circuit, then DTC P0712 sets. DTC P0712 is a type A DTC.


CONDITIONS FOR SETTING THE DTC

^ No System Voltage Malfunction DTC P0560 is set.

^ The ignition is ON.

^ The PCM detects a TFT sensor voltage of 0.20 volts or less for 10 seconds.


ACTION TAKEN WHEN THE DTC SETS

^ The PCM uses a default transmission fluid temperature of 170°C (338°F) for transmission operation.

^ The PCM illuminates the Malfunction Indicator Lamp (MIL).

CONDITIONS FOR CLEARING THE MIL/DTC

^ The PCM turns OFF the MIL after three consecutive ignition cycles without a failure reported.

^ A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.

^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

DIAGNOSTIC AIDS

^ Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring at the transmission 7-way connector. Look for the following conditions:

- A bent terminal

- A backed out terminal

- A damaged terminal

- Poor terminal tension

- A chafed wire

- A broken wire inside the insulation

^ When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.

^ Inspect the transmission harness for a short to ground. Inspect the engine harness for a short to ground.

^ Inspect the transmission cooling system for blockage or other restrictions.

TEST DESCRIPTION

The numbers below refer to the step numbers on the diagnostic chart.

3. A scan tool display of 138°C (28O°F) or more indicates that this DTC is current.

4. This action isolates the fault between the transmission harness and the engine harness.