P0571

P0571-BRAKE SWITCH 1 PERFORMANCE





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

This diagnostic is designed to detect a faulty brake switch. The algorithm starts to run when the operator is driving above 30 mph (48 kmh) for more than five minutes. If after that time vehicle speed drops to below 2 mph (3 kmh) and the Powertrain Control Module (PCM) does not detect brake activity the diagnostic will fail. The PCM will turn on the ETC lamp immediately after the diagnostic runs and fails.

- When Monitored:
Engine speed is above 30 mph (48 kmh) for more than five minutes

- Set Condition:
Vehicle speed is detected at 2 mph (3 kmh) without brake activity.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. OTHER DTCS
1. With the scan tool, read DTCs.

Are other DTCs present?

Yes

- Troubleshoot other DTCs first.

No

- Go To 2

2. POWERTRAIN CONTROL MODULE
1. Interview customer. This fault can be set if the customer coasts to a vehicle speed below 2 mph (3 kmh) by using the parking brake or exhaust brake.

Did the customer coast to a near stop without using the service brake?

Yes

- Explain diagnostic operation to customer. Repair complete.

No

- Replace the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.