4L80-E / 4L85-E Automatic Transmission
DTC P0724 (4.8L and 6.0L)
Circuit Description
The torque converter clutch (TCC) brake switch indicates the brake pedal status. The normally closed TCC brake switch supplies a B+ signal to the powertrain control module (PCM). The signal voltage circuit opens when the brakes are applied.
If the PCM detects a closed TCC brake switch during decelerations, then DTC P0724 sets. DTC P0724 is a type C DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0724 Brake Switch Circuit High Voltage
Conditions for Running the DTC
* No VSS DTCs P0502 or P0503.
* The ignition switch is in the ON position.
* The system voltage is 8-12 volts.
Conditions for Setting the DTC
DTC P0724 sets if the PCM detects a closed brake switch or circuit, 12 volts, during vehicle deceleration and the following conditions occur ten times:
* The vehicle speed is greater than 40 km/h (25 mph) for 7 seconds.
* Then, the vehicle speed is 8-40 km/h (5-25 mph) for 2.5 seconds.
* Then, 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 records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Failure Records.
* 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 warm-up cycles without a non-emission related diagnostic fault occurring.
Diagnostic Aids
Inspect the brake switch for proper mounting and operation.
Test Description
The number below refers to the step number on the diagnostic table.
3. This step isolates the TCC brake switch as a source for setting the DTC.
