P0572

Diagnostic Chart:

Schematic:

The stop lamp switch is used to turn On the stop lamps and serve as an input to the PCM and cruise control module (if equipped). The stop lamp switch has two internal independent switches; one is used for the stop lamps and the other for the PCM/cruise control module inputs. The switch for the PCM/cruise control module is closed and the switch for the stop lamps is open with brake pedal released and switch adjusted properly. Ignition voltage is supplied to the PCM and cruise control module through the stop lamp switch whenever the ignition is turned On and the brake pedal is released. When the brake pedal is depressed, the PCM/cruise control module inputs go low. The PCM monitors the stop lamp input for low and high voltage faults under certain conditions. DTC P0572 sets when the vehicle has been driven twice up to a calibrated vehicle speed and the voltage at the PCM remains low, indicating the brake pedal is always being applied.

DTC PARAMETERS
DTC P0572 will set if no voltage is present at the PCM stop lamp switch input when the vehicle has cycled from 0-60 km/h (0-37 mph) twice in one ignition cycle.

DTC P0572 diagnostic runs continuously once the above conditions have been met.

DTC P0572 is a type D DTC.

DIAGNOSTIC AIDS
DTC P0572 can set falsely if the customer has driven the vehicle up to the calibrated vehicle speed twice while coming to a stop both times with his foot On the brake.

To locate an intermittent problem, use Scan tool to monitor BRAKE SWITCH while wiggling wires. The Scan tool will read RELEASED when ignition voltage is present at the PCM cruise/brake input. Wiggling wires while watching for a change from RELEASED to APPLIED may locate the area where an open or short to ground in the wiring could lie.

Make sure the brake switch is adjusted properly by watching the stop lamps go On and Off. A switch that is too far from the brake pedal and won't close and may set this DTC.