Brake Switch Functionality

Overview

This procedure does not relate to any specific fault code, but verifies that the UltraShift PLUS transmission is receiving service brake switch input and park brake switch input from the vehicle.

Possible Causes

  • Service Brake Switch
    • Internal failure
  • Park Brake Switch
    • Internal failure
  • Other
    • See Vehicle OEM for further possible causes

Brake Switch Functionality Test

A
Purpose:Monitor Service Brake Switch in ServiceRanger.
  1. Key on with engine off.

  2. Connect ServiceRanger.

  3. In ServiceRanger, go to Data Monitor.

  4. Select the “Engine and Brake” default parameter file.

  5. Monitor Parameter 597 “Brake Switch”.

  6. Depress Service Brake and verify that Brake Switch status changes to “Depressed”.

  7. Release Service Brake and verify that Brake Switch status changes to “Released”.

    Note: ServiceRanger covers Brake Switch status input from several possible sources. If the vehicle uses a Brake Switch source other than those programmed in ServiceRanger, the use of an OEM diagnostic tool may be required to see Brake Switch status.

  • If parameter matches Service Brake position, Go to Step B

  • If parameter does not match Service Brake position, repair Brake Switch input to the Transmission Electronic Control Unit (TECU) per OEM guidelines.

B
Purpose:Monitor Parking Brake Switch Status in ServiceRanger.
  1. Within Data Monitor, Monitor Parameter 70 “Parking Brake Switch Status”.

  2. Set Parking Brake Switch in the cab and verify that Brake Switch status changes to “Set”.

  3. Release Parking Brake Switch in the cab and verify that Parking Brake Switch Status changes to “Not set”.

  • If parameter does not match Parking Brake Switch position, repair Parking Brake Switch input to the Transmission Electronic Control Unit (TECU) per OEM guidelines.

  • If parameter matches Parking Brake Switch position, no problem was detected, test complete.