Detroit DD15 EPA07 (2007-09) Fault Code: SPN 84 FMI 14 (CPC) J1939 Wheel-Based Vehicle Speed Signal from Source #3 is Missing

NOTE: If codes for other modules are present, fix those first.

1. Improper programming of the CPC (Common Powertrain Controller).
2. Other failed modules on the truck (Transmission, ABS, Cab controller, etc…).
3. Battery/battery cable issues, or electical issue on truck.