P0573

DTC P0573

DTC DESCRIPTOR

DTC P0573
Brake Switch Circuit 1 High Voltage




DIAGNOSTIC FAULT INFORMATION

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection

CIRCUIT/SYSTEM DESCRIPTION
The brake pedal position sensor is used to sense the action of the driver application of the brake pedal. The brake pedal position sensor provides an analog voltage signal that will increase as the brake pedal is applied. The body control module (BCM) provides a low reference signal and a 5-volt reference voltage to the brake pedal position sensor. When the variable signal reaches a voltage threshold indicating the brakes have been applied, the BCM will apply battery positive voltage to the stop lamps, center high mounted stop lamp (CHMSL), transmission control module (TCM), and engine control module (ECM). The stop lamps will not operate unless the ignition is in the ON position.

CONDITIONS FOR RUNNING THE DTC
- The ignition is ON.
- Battery voltage is greater than 11.5 volts.

CONDITIONS FOR SETTING THE DTC
This DTC will set when the ECM detects an open or short to voltage on the stop lamp switch signal circuit when the serial data message from the BCM indicates the brakes are applied.

ACTION TAKEN WHEN THE DTC SETS
- The ECM stores the DTC to memory.
- The ECM will record the operating conditions at the time the diagnostic failed. The ECM stores this information in Failure Records.

CONDITIONS FOR CLEARING THE DTC
- The condition responsible for setting the DTC no longer exists.
- You issue a scan tool CLEAR DTCs command.
- A history DTC will clear once 40 malfunction-free ignition cycles have occurred.

DIAGNOSTIC AIDS

IMPORTANT: The stop lamps will not illuminate unless the ignition is in the ON position. For more detailed information concerning stop lamp operation, refer to Exterior Lighting Systems Description and Operation.

Verify that the brake pedal position sensor is properly calibrated.

CIRCUIT/SYSTEM TESTING
1. Ignition ON, install a scan tool and recalibrate the brake pedal position sensor, clear all DTCs, and operate the vehicle within the Conditions for Running the DTC.
- If DTC P0573 resets as current, repair the stop lamp switch signal circuit for a short to voltage or an open/high resistance.
2. If all circuits test normal, replace the ECM.

REPAIR INSTRUCTIONS

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

- Control Module References for ECM replacement, setup, and programming
- Brake Pedal Position Sensor Calibration