Fault Code 127: Cruise Control Active
J1939: SA 3 SPN 595 FMI 13, 19
Overview
The Transmission Control Module (TCM) receives the vehicle’s Cruise Control Active 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 Cruise Control Active 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: Cruise Control Active messages not available for 5 seconds.
FMI 19: Received Network Data In Error: Cruise Control Active messages invalid for 5 seconds.
Fallback
FMI 13, 19:
- Amber warning lamp on
- Urge to Move and Creep Mode prohibited
Conditions to Set Fault Code Inactive
FMI 13, 19: Cruise Control Active messages received and valid for 10 seconds.
Possible Causes
FMI 13, 19:
- Vehicle Components - Vehicle ECU(s)
- Vehicle Cruise Control Active J1939 message not enabled
- Other vehicle ECU(s) faulted
- Vehicle Harness - Primary Data Link (J1939A)
- Shorted to power, shorted to ground or open circuit
- Terminals bent, spread, corroded, or loose
Note: Refer to OEM for troubleshooting a failed system.
Additional Tools
- None
Fault Code 127 Troubleshooting
Record the transmission fault codes, FMIs, occurrences, and timestamps from the Service Activity Report created during the Diagnostic Procedure.
If Fault Code 127 is Inactive and there are other Active vehicle or transmission fault codes, troubleshoot all Active fault codes.Go to Step V
If Fault Code 127 FMI 13 is Active, refer to OEM and enable vehicle Cruise Control Active message (SPN 595). Go to Step V
If Fault Code 127 FMI 13 is Inactive, Go to Step V
If Fault Code 127 FMI 19 is Active or Inactive, refer to OEM guidelines for repair of the vehicle Cruise Control Active message (SPN 595). 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 127 sets Active during operation, Go to Step A
If a fault code other than 127 sets Active, troubleshoot per Fault Code Isolation Procedure Index.