AIR SUSPENSION SYSTEM (2500/3500 MODELS) —
IF EQUIPPED
Description
This air suspension system is a rear leveling ride height
system. The main purpose of this system is to maintain the
truck’s rear ride height level. There are two selectable
heights that can be chosen based on your operating condi-
tions.
The system requires that the ignition be in ON/RUN
position or the engine running with zero vehicle speed for
all user requested changes and load leveling.
Normal Ride Height (NRH) – This is the standard position
of the suspension and is meant for normal driving. It will
automatically adjust to maintain the rear ride height as
conditions change.
Alternate Trailer Height (ATH) – Lowers the vehicle
approximately 1 in (25 mm) for a level truck, to be used as
required while trailer towing. It will automatically adjust
to maintain the rear ride height as conditions change.
Trailer Decoupling/Unloading - The air suspension sys-
tem will load level (lower/exhaust only) for up to 10
minutes after the vehicle is turned off. This allows for easy
removal of a trailer and/or load from the back of the truck
by maintaining the ride height. After 10 minutes you will
need to turn the ignition to the run position for the air
suspension to maintain ride height. If the air suspension
system is disabled using the settings menu (Tire Jack Mode,
Transport Mode or Alignment Mode) the system will
remain disabled when the vehicle is turned off. Reactivat-
ing the air suspension can be accomplished via the settings
menu or driving the vehicle above 5 mph (8 km/h) for Tire
Jack Mode or Alignment Mode and 16 mph (26 km/h) for
Transport Mode.
Rear Leveling Ride Height Switch
356 STARTING AND OPERATING