The "bus" is the system the computers on the Ram use to "talk" to each other. The "no bus" message on the odometer means that the system has failed. You will need access to a scan tool to diagnose. Any computer on the truck or any of the wires in between can cause this problem.
Low oil pressure
Camshaft position sensor circuit malfunction.
Trouble code P0234 means:Engine overboost condition
Trouble code P0177 means:Fuel composition sensor circuit range/performance
Trouble code P1693 means: A companion DTC was set in both the ECM and PCM
Trouble code P0483 means: Fan Performance
Trouble code P0573 means:Cruise control/brake switch A circuit high
my book says code 0123 THROTTLE/PEDAL POSITION SENSOR/SWITCH A CIRCUIT HIGH INPUT
#2 warm air heater relay wiring fault
Trouble code P0680 means: Reserve for future glow plugs 9-12
P0483 radiator fan speed incorrect. You need to replace the fan clutch.
P1693 : Dtc detected in the companion module. You need to check the Ecm and Pcm for codes. Which ever did not have p1693 will have a code.