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 no 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.
- Inspect for proper adjustment of the stop lamps. Refer to 69011.
- For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections. Component Tests and General Diagnostics
- Inspect for proper adjustment of the cruise control release switch. Refer to 10766.

TEST

Step 1 - Step 10:

Step 11 - Step 14: