Fault Code 158: XBR Active Control Mode

J1939: SA 3 SPN 2918 FMI 9, 13, 19

Overview

The Transmission Control Module (TCM) receives the vehicle’s eXternal Brake Request (XBR) Active Control Mode 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 Active Control Mode messages. If messages are not received or are invalid, the fault is set Active.

Conditions to Set Fault Code Active

FMI 9 - Abnormal Update Rate: XBR Active Control Mode message not received for 5 seconds.

FMI 13 - Out of Calibration: XBR Active Control Mode message not available for 5 seconds.

FMI 19 - Received Network Data in Error: XBR Active Control Mode messages invalid for 5 seconds.

Fallback

FMI 9, 13, 19:

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

Conditions to Set Fault Code Inactive

FMI 9, 13, 19: XBR Active Control Mode messages received and valid for 10 seconds.

Possible Causes

FMI 9, 13, 19:

  • Vehicle Components
    • XBR Active Control Mode message not enabled
    • Other vehicle ECU(s) faulted
  • Vehicle Harness - Primary Data Link (J1939A)
    • Wiring shorted to power, shorted to ground or open
    • Terminals bent, spread, corroded, or loose

Note: Refer to OEM for troubleshooting a failed system.

Additional Tools

  • None

Fault Code 158 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 158 is Inactive and there are other Active vehicle or transmission fault codes, troubleshoot all Active fault codes. Go to Step V

  • If Fault Code 158 FMI 9, 19 is Active or Inactive, refer to OEM guidelines for repair of the vehicle XBR Active Control Mode message (SPN 2918). Go to Step V

  • If Fault Code 158 FMI 13 is Active, Go to Step B

  • If Fault Code 158 FMI 13 is Inactive, the XBR Active Control Mode message is available. Go to Step V

B
Purpose:Verify External Braking Integration configuration and availability of vehicle XBR Active Control Mode message.
  1. Key on with engine off.

  2. Connect ServiceRanger.

  3. Go To “Configuration”.

  4. Select “Vehicle”.

  5. Record "External Braking Integration" Current Value.

  6. Refer to OEM and verify availability of the vehicle XBR Active Control Mode message (SPN 2918) from an OEM ECU.

  • If message is available, refer to OEM and enable vehicle XBR Active Control Mode message (SPN 2918). Go to Step V

  • If message is not available and the "External Braking Integration" Current Value indicates “Supported”, select “Not Supported” from New Value drop down list and follow on-screen prompts. Go to Step V

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.