Fault Code 138: Halt Brake Switch
J1939: SA 3 SPN 2911 FMI 9, 11, 12, 13, 14, 19
Overview
The Transmission Control Module (TCM) receives the vehicle’s Halt Brake Switch 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 Halt Brake Switch 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: Halt Brake Switch message not received for 5 seconds.
FMI 11 - Root Cause Unknown: Halt Brake Switch messages invalid for 1 second.
FMI 12 - Bad Intelligent Device: TCM incorrectly configured.
FMI 13 - Out of Calibration: Halt Brake Switch message not available for 5 seconds.
FMI 14 - Special Instructions: Halt Brake Switch message not received during launch for 1 second.
FMI 19 - Received Network Data in Error: Halt Brake Switch messages invalid for 5 seconds.
Fallback
All FMIs:
- Amber warning lamp on
- Urge to Move and Creep Mode prohibited
Note: Vehicle may have additional fallback modes. Refer to OEM.
Conditions to Set Fault Code Inactive
All FMIs: Halt Brake Switch messages received and valid for 10 seconds.
Possible Causes
FMI 9, 11, 13, 14, 19:
- Vehicle Components
- Halt Brake Switch message not enabled
- Halt Brake Switch internal failure
- 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.
FMI 12:
- TCM
- Incorrect configuration - Hill Start Aid disabled on vehicle equipped with Halt Brake Switch.
Additional Tools
- None
Fault Code 138 Troubleshooting
Record the transmission fault codes, FMIs, occurrences, and timestamps from the Service Activity Report created during the Diagnostic Procedure.
If Fault Code 138 is Inactive and there are other Active vehicle or transmission fault codes, troubleshoot all Active fault codes. Go to Step V
If Fault Code 138 FMI 9, 11, 14, 19 is Active or Inactive, refer to OEM guidelines for repair of the vehicle Halt Brake Switch message (SPN 2911). Go to Step V
If Fault Code 138 FMI 12 is Active, Go to Step B
If Fault Code 138 FMI 12 is Inactive, Hill Start Aid is properly configured. Go to Step V
If Fault Code 138 FMI 13 is Active, refer to OEM and enable vehicle Halt Brake Switch message (SPN 2911). Go to Step V
If Fault Code 138 FMI 13 is Inactive, Go to Step V
Key on with engine off.
Connect ServiceRanger.
Go To “Configuration”.
Select “Options”.
Record “Hill Start Aid” Current Value.
Select “Enabled” option from “New Value” drop down list, select “Apply” and follow on-screen prompts.
Note: Contact OEM or customer for appropriate vehicle Hill Start Aid “Enabled” option.
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 138 sets Active during operation, Go to Step A
If a fault code other than 138 sets Active, troubleshoot per Fault Code Isolation Procedure Index.