P0571

P0571-BRAKE SWITCH 1 PERFORMANCE

For a complete wiring diagram refer to the Wiring Information Electrical Diagrams.

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 5 minutes. If after that time vehicle speed drops to below 2 mph (3 kmh) and the ECM does not detect brake activity the diagnostic will fail. The ECM 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 5 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 DTC'S
1. With the scan tool, read DTC's.

Are other DTCs present?

Yes

- Troubleshoot other DTCs first.

No

- Go To 2

2. ECM
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 ECM.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L.Powertrain Verification Test