DTC P1586: Decrease In Vehicle Speed Without A Switch Signal (3.8L Engine): Description

Torque Converter Clutch (TCC)/brake switch is normally a closed switch that supplies battery voltage to Powertrain Control Module (PCM). Applying brake pedal opens TCC/brake switch, interrupting voltage to PCM. This DTC is for manual transmission vehicles only, this switch is used for TCC operation on automatic transmission vehicles. If vehicle speed decreases in one MPH increments without PCM sensing a signal of stoplight switch contacts, or condition exists for 10 accel/decel cycles, DTC P1586 will set.