P0724

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The TCC/Shift Interrupt switch indicates the brake pedal status. This normally-closed switch within the Brake Switch Assembly, supplies a B+ signal on circuit 420 to the PCM. The signal voltage circuit opens when you apply the brakes. The PCM uses this signal to de-energize the TCC Solenoid Valve. When the PCM detects a closed brake switch during a deceleration, then DTC P0724 sets. DTC P0724 is a type D DTC.

CONDITIONS FOR SETTING THE DTC

^ No Vehicle Speed Sensor (VSS) DTC P0502

^ The PCM detects a closed TCC/Shift Interrupt switch/circuit (12 volts) for 2 seconds and the following events occur seven consecutive times:

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

^ Then the vehicle speed is between 8 and 32 km/h (5 and 20 mph) for 4 seconds; Then the vehicle speed is less than 8 km/h (5 mph).

ACTION TAKEN WHEN THE DTC SETS

^ The freeze shift adapts from being updated.

^ The PCM will 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.

^ 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 any poor electrical connections at the PCM. Inspect the wiring at the brake switch assembly. 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 an open condition, massage the wiring harness while watching the test equipment for changes.

^ Ask the customer about the customer's driving habits. Ask if the customer has any unusual driving conditions (e.g. stop-and-go, expressway, etc.).

^ Check for the most current calibration ID. Check for the latest bulletin.

^ Inspect the brake switch assembly for proper mounting and adjustment.

TEST DESCRIPTION

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

3. This Step tests for voltage at the brake switch Assembly.

6. This Step tests the TCC/Shift Interrupt switch.