Fault Code 157: XBR System State

J1939: SA 3 SPN 2917 FMI 13

Overview

The Transmission Control Module (TCM) receives the vehicle’s eXternal Brake Request (XBR) System State message from a vehicle Electronic Control Unit (ECU) over the Primary Data Link (J1939A). This information is used to determine transmission operation.

Detection

The TCM monitors XBR System State messages. If messages are not received or are invalid, the fault is set Active.

Conditions to Set Fault Code Active

FMI 13 - Out of Calibration: XBR System State message is available but TCM is not configured to support External Braking Integration.

Fallback

FMI 13:

  • Amber warning lamp on
  • Urge to Move and Creep Mode prohibited

Conditions to Set Fault Code Inactive

FMI 13: External Braking Integration configuration is properly configured in the TCM.

Possible Causes

FMI 13:

  • External Braking Integration is not configured in the TCM to support the XBR System State message.

Additional Tools

  • None

Fault Code 157 Troubleshooting

A
Purpose:Check for Active or Inactive fault codes.
  1. Set vehicle parking brake and chock wheels.

  2. Record transmission fault codes, FMIs, occurrences, and timestamps from Service Activity Report created during the Diagnostic Procedure.

  • If Fault Code 157 is Inactive and there are other Active vehicle or transmission fault codes, troubleshoot all Active fault codes. Go to Step V

  • If Fault Code 157 FMI 13 is Active, Go to Step B

  • If Fault Code 157 FMI 13 is Inactive, External Braking Integration configuration is properly configured. Go to Step V

B
Purpose:Verify External Braking Integration configuration.
  1. Key on with engine off.

  2. Connect ServiceRanger.

  3. Go To “Configuration”.

  4. Select “Vehicle”.

  5. Record "External Braking Integration" Current Value.

  • If External Braking Integration Current Value indicates “Not Supported”, select appropriate "Supported” option and follow on-screen prompts. Go to Step V

    Note: Contact OEM for vehicle External Braking Integration system "Supported" option.

V
Purpose:Verify Repair.
  1. Key off.

  2. Reconnect all connectors and verify all components are properly installed.

  3. Key on with engine off.

  4. Connect ServiceRanger.

  5. Go To “Fault Codes”.

  6. Select “Clear All Faults”.

  7. Operate vehicle and attempt to reset the fault code or duplicate the previous complaint.

  8. Check for fault codes using ServiceRanger.