P0724

CIRCUIT DESCRIPTION

The Torque Converter Clutch (TCC) brake switch reports brake pedal status to the Powertrain Control Module (PCM). The brake switch indicates that the brake pedal is either applied or released. This normally-closed switch supplies battery voltage on circuit 420 to the PCM. Applying the brake pedal opens the brake switch, interrupting voltage to the PCM. When the PCM receives 0 volts at the brake switch input, the PCM turns OFF the TCC Solenoid Valve.

When the PCM detects a closed brake switch (stuck OFF) during deceleration, then DTC P0724 sets. DTC P0724 is a type D DTC.


CONDITION FOR SETTING THE DTC

^ No Vehicle Speed Sensor (VSS) DTC P0502.

^ The vehicle speed is greater than 32 km/h (20 mph) for 6 seconds.

^ The vehicle speed decreases to 8 km/h (5 mph) and takes 4 seconds.

^ The vehicle speed is less than 8 km/h (5 mph).

^ The above conditions must occur 7 times with the brake switch continuously OFF, and without the PCM receiving a voltage input for 2 seconds.

ACTION TAKEN WHEN THE DTC SETS

The PCM does not illuminate the Malfunction Indicator Lamp (MIL).


CONDITIONS FOR CLEARING THE DTC

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.


DIAGNOSTIC AIDS

^ Ensure that the TCC brake switch is properly adjusted.

^ Check PCM calibration for a current update.

^ 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.

TEST DESCRIPTION

The step number below refers to the step numbers on the diagnostic table.

2. A scan tool display that changes from Closed to Open when the brake switch is disconnected indicates a faulty brake switch.