The Transmission Control Module (TCM) receives the vehicle’s eXternal Brake Request (XBR) Active Control Mode message over the Primary Data Link. This information is used to determine transmission operation.
The TCM monitors the XBR Active Control Mode message. If a failure is detected the fault is set 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: XBR Active Control Mode message invalid for 5 seconds.
FMI 9, 13, 19:
FMI 9, 13, 19: XBR Active Control Mode message valid for 10 seconds.
FMI 9, 13, 19:
Record the transmission fault codes, FMIs, occurrences, and timestamps from the 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 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
If Fault Code 158 FMI 9 or 19 is Active or Inactive, refer to OEM guidelines regarding XBR Active Control Mode message repair or replacement. Go to Step V
Key on.
Connect ServiceRanger.
Go To “Configurations”.
Select “Vehicle”.
Record External Braking Integration Current Value.
Refer to OEM and verify availability of the vehicle XBR Active Control Mode SPN 2918 message.
If the vehicle XBR Active Control Mode SPN 2918 message is available, refer to OEM and enable vehicle XBR Active Control Mode SPN 2918 message. Go to Step V
If the vehicle XBR Active Control Mode SPN 2918 message is not available and the External Braking Integration Current Value in ServiceRanger indicates “Supported”, select “Not Supported” and follow on-screen prompts. Go to Step V
Key off.
Reconnect all connectors and verify that all components are properly installed.
Key on with engine off.
Connect ServiceRanger.
Go to “Fault Codes”.
Select “Clear All Faults”.
Operate vehicle and attempt to reset the fault code or duplicate the previous complaint.
Check for fault codes using ServiceRanger.
If no fault codes set and the vehicle operates properly, test complete.
If Fault Code 158 sets Active during operation, Go to Step A
If a fault code other than 158 sets Active, troubleshoot per Fault Code Isolation Procedure Index.