P0571

DTC P0571

CIRCUIT DESCRIPTION




The cruise/brake switch signal circuit is a normally closed switch. The stop lamp switch signal circuit is a normally open switch. When the brake pedal is released, the ECM/PCM 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.

CONDITIONS FOR RUNNING THE DTC
- The ignition is ON.
- The traction control system or the antilock brake system have not failed.

CONDITIONS FOR SETTING THE DTC
- When the brake pedal is released, the ECM/PCM detects a high voltage signal on the stop lamp switch signal circuit or when the ECM/PCM detects a low voltage signal on the cruise/brake switch signal circuit.
- The above conditions are present for 1.5 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The ECM/PCM stores the DTC information into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL) will not illuminate.
- The ECM/PCM records the operating conditions at the time the diagnostic fails. The ECM/PCM 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.
- Inspect for proper adjustment of the cruise control release switch.
- For an intermittent condition, refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.

TEST

Steps 1-9: