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

A
Purpose:Check for Active or Inactive fault codes.
  1. 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

V
Purpose:Verify Repair.
  1. Key off.

  2. Reconnect all connectors and verify that 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.