P0724

Circuit Description

The TCC brake switch reports brake pedal status to the PCM. The TCC brake switch indicates that the brake pedal is either applied or released. The normally-closed switch supplies battery voltage to the PCM. Applying the brake pedal opens the TCC brake switch, interrupting voltage to the PCM. When the PCM receives 0 volts at the TCC brake switch input, the PCM turns OFF the torque converter clutch pulse width modulation (TCC PWM) solenoid valve.

If the PCM detects a closed TCC brake switch (indicating pedal released) during deceleration, then DTC P0724 sets. DTC P0724 is a type D DTC.

Conditions for Running the DTC

No VSS DTCs P0502 or P0503.

Conditions for Setting the DTC

The TCC brake switch indicates continuously CLOSED (12 volts) while the following conditions occur 7 times:

^ The vehicle speed is greater than 32 km/h (20 mph) for 6 seconds;
^ Then the vehicle speed decreases to 8 km/h (5 mph) and takes 4 seconds;
^ Finally, the vehicle speed is less than 8 km/h (5 mph).

Action Taken When the DTC Sets

^ The PCM does not illuminate the malfunction indicator lamp (MIL).
^ The PCM stores DTC P0724 in PCM history.

Conditions for Clearing the DTC

^ A scan tool clears the DTC from PCM history.
^ The PCM clears the DTC from PCM history if the vehicle completes 40 consecutive warm-up cycles without a non-emission-related diagnostic fault occurring.
^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids

^ Inspect the wiring at the PCM, the TCC brake switch connector and all other circuit connecting points for the following conditions:
- A backed out terminal
- A damaged terminal
- Reduced terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
- Corrosion
^ When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.

Test Description

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

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