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 powertrain control module (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. When the brake pedal is applied, the cruise/brake switch opens and the stop lamp switch closes. The PCM detects a low voltage signal on the cruise brake switch signal circuit and a high voltage signal on the stop lamp switch signal circuit.

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

CONDITIONS FOR SETTING THE DTC
- The PCM 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 PCM stores the DTC information into memory when the diagnostic runs and fails.
- The service vehicle soon indicator may illuminate.
- The malfunction indicator lamp (MIL) will not illuminate.
- The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.The cruise control system is disabled.

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 Diagnostic Aids for Circuit Testing and Wiring Repair procedures.

TEST

Steps 1 - 11:

Steps 12 - 14: