Dodge 2007 Ram Chassis Cab - Manual (Page 256)

NOTE: When a diesel engine is allowed to run out of
fuel or the fuel gels at low temperatures, air is pulled into
the fuel system.
You may try priming as described below.
1. Add a substantial quantity of fuel to the tank (5 to 10
gallons) or eliminate the gelled fuel condition.
2. Crank the engine for 1 to 2 seconds. If the engine does
not start, then release the key or starter button back to the
RUN position (do not turn the key back to the OFF
position). The electric fuel transfer pump will continue to
run and purge air from the system for about 20 seconds.
After 20 seconds, attempt to start the engine again.
3. Start the engine using the Normal Starting Procedure.
4. Repeat the procedure if the engine does not start.
WARNING!
Do not open the high pressure fuel system when
cranking the engine or with the engine running.
Engine operation causes high fuel pressure. High
pressure fuel spray can cause serious injury or death.
NOTE: The engine may run rough until the air is forced
from all the fuel lines.
256 STARTING AND OPERATING