There is a TSB that sorta address the issue you are having. TSB # 14-002-05. Here is part of the description....
SUBJECT:
InactiveThrottle Body In Cold Ambient Temperatures
OVERVIEW:
This bulletin involves replacing the throttle body.
MODELS:
2003 - 2005 (DR) Ram Truck
NOTE: This Bulletin Applies To Vehicles Equipped With 5.7L Engines (Sales Code
EZA).
SYMPTOM/CONDITION:
Customers may experience any of the following Electronic Throttle Control (ETC) system
symptoms at start up in extreme cold ambient temperatures (Below 0° F (minus 18°C)):
Partial Return From Cold Start Fast Idle
No RPM Increase When Accelerator Pedal Is Moved
Diagnostic Trouble Code 2110 - Throttle Actuator Control System - Forced Limited
RPM
Diagnostic Trouble Code 2118 - Throttle Actuator Control Motor - Current
Range/Performance
DIAGNOSIS:
If a customer indicates that they have experienced the condition, perform the Repair
And a full view of it here >>>>>
http://dodgeram.info/tsb/2005/14-002-05.htm