4WD Lamp Illuminated and Diagnostic Trouble Code C140F Active in Final Drive Control Modules (FDCM) Memory
This bulletin involves verifying FDCM software level and then flash reprogramming of the FDCM with new software.
Customers may indicate that the ?Service 4WD? indicator in the instrument cluster is illuminated. They may also
indicate that the transfer case will not shift from 4WD High, 4WD Low, and/or Neutral once the lamp is illuminated. Further investigation identifies that a Diagnostic Trouble Code C140F is stored or active in the Final Drive Control Modules
(FDCM) Memory
