That brake switch may just be your problem than...
"The brake switch indicates brake pedal status to the powertrain control module (PCM). The brake switch is a normally-closed switch that supplies battery voltage on the input circuit to the PCM. Applying the brake pedal opens the switch, interrupting voltage to the PCM. When the brake pedal is released, the PCM receives a constant voltage signal. If the PCM receives a zero voltage signal at the brake switch input, and the torque converter clutch (TCC) is engaged, the PCM de-energizes the TCC solenoid valve."
"Diagnostic Aids
Inspect the brake switch for proper mounting and operation.
Inspect for ABS DTCs. A faulty ABS condition may contribute to setting DTC P0724."