P0724

CIRCUIT DESCRIPTION

The Torque Converter Clutch (TCC) brake switch is used to indicate the status of the brake pedal (applied or released).

When the Powertrain Control Module (PCM) detects a status change on the brake lamp circuit and the extended travel brake switch input without a transition on the TCC brake switch input, then DTC P0724 sets. DTC P0724 is a Type C DTC.

CONDITIONS FOR SETTING THE DTC

^ No Vehicle Speed (VSS) sensor DTCs P0502 or P0503 are set.
^ No extended travel brake switch or stop lamp switch DTCs P1574 or P1575 are set.
^ No loss of PCM serial data DTC P1602 is set.
^ The TCC brake switch input indicates ignition volts.
^ Traction control or ABS has not failed.
^ The difference in vehicle speed and a non-driven wheel speed is less than 10 km/h (6 mph).
^ DTC P0724 has not passed this ignition cycle.
^ The following conditions must occur 7 times without a status change on the TCC brake input:

1. Vehicle speed is greater than 32 km/h (20 mph) for more than 6 seconds.
2. Then the vehicle speed decreases to 8 km/h (5 mph) taking longer than 2 seconds.

ACTION TAKEN WHEN THE DTC SETS

^ SERVICE ELECTRICAL SYSTEM displays on the Driver Information Center (DIC).
^ The PCM uses the extended travel brake switch input or the stop lamp switch input for TCC control.
^ The PCM disables garage shift adapts.

CONDITIONS FOR CLEARING THE DIC/DTC

^ The TCC brake switch input must indicate
^ volts for a minimum of 2 seconds.
^ 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

^ Inspect the TCC brake switch for proper adjustment.
^ Check the customer's driving habits.
^ Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical connections at the brake switch connector. Look for the following problems:

- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire

^ 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. This step isolates the brake switch as the source for setting the DTC.
4. This step inspects circuit 420 for a short to power, if the scan tool status never changes from released to applied.