P0571
DTC P0571
Circuit Description
The cruise/brake switch is a normally closed switch and the stop lamp switch is a normally open switch. When the brake pedal is released, the engine control module (ECM) detects a high voltage signal on the cruise/brake switch signal circuit and a low signal voltage signal on the stop lamp switch signal circuit. When the brake pedal is applied, the cruise/brake switch opens and the stop lamp switch closes. The ECM detects a low voltage signal on the cruise brake switch signal circuit and a high voltage signal on the stop lamp switch signal circuit.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0571 Cruise Control Brake Switch Circuit
Conditions for Running the DTC
* DTCs P0717, P0722, and C0161 are not set.
* The engine speed is greater than 700 RPM.
* The Traction Control System (TCS) or the Antilock Brake System (ABS) are not active or have not failed.
Conditions for Setting the DTC
* The ECM detects a transition of the stop lamp switch without detecting a transition of the cruise/brake switch during a deceleration event.
* This diagnostic run continuously with the ignition ON.
Action Taken When the DTC Sets
* The ECM stores the DTC information into memory when the diagnostic runs and fails.
* The malfunction indicator lamp (MIL) will not illuminate.
* The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records.
Conditions for Clearing the DTC
* A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
* A history DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
* Use a scan tool in order to clear the DTC.
Diagnostic Aids
In order to avoid a misdiagnosis, perform the following:
* Inspect for proper operation of the stop lamps.
* For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids. Component Tests and General Diagnostics
Test
