fault code

DTC P1693 is DTC Detected in PCM. The Cummins Diesel equipped trucks have 2 Engine Computers. The ECM is a Cummins module which controls all Fuel/Emission related functions. The PCM is a Chrysler (JTEC) Controller which controls all A/C, Charging, Cruise Control, Fuel pump and Transmiaaion system functions. A Chrysler DRB3 Scan tool will have a screen to show which module to access for diagnostics. Generic scan tools may not. You will have to access the PCM to retrieve the diagnostic code stored.