Page 707 of 916

Repeat steps 8 and 9 until the GAIN setting is at a point
just below trailer wheel lockup. If towing a heavier
trailer, trailer wheel lockup may not be attainable even
with the maximum GAIN setting of 10.
Light Electric Heavy Electric Light EOH Heavy EOH
Type of Trailer
BrakesElectric Trailer
BrakesElectric Trailer
BrakesElectric over Hy-
draulic Trailer
BrakesElectric over Hy-
draulic Trailer
Brakes
Load *Under 10,000 lbs *Above 10,000 lbs *Under 10,000 lbs *Above 10,000 lbs
* The suggested selection depends and may change
depending on the customer preferences for braking per-
formance. Condition of the trailer brakes, driving and
road state may also affect the selection.
Display Messages
The trailer brake control interacts with the Electronic
Vehicle Information Center (EVIC) or Driver InformationDisplay (DID). Display messages, along with a single
chime, will be displayed when a malfunction is deter-
mined in the trailer connection, trailer brake control, or
on the trailer. Refer to “Electronic Vehicle Information
Center” or “Driver Information Display” in “Under-
standing Your Instrument Panel” for further information.
5
STARTING AND OPERATING 705
Page 731 of 916

JACKING AND TIRE CHANGING
Jacking And Tire Changing 1500 Series Trucks
WARNING!
•Do not attempt to change a tire on the side of the
vehicle close to moving traffic. Pull far enough off
the road to avoid the danger of being hit when
operating the jack or changing the wheel.
•Being under a jacked-up vehicle is dangerous. The
vehicle could slip off the jack and fall on you. You
could be crushed. Never put any part of your body
under a vehicle that is on a jack. If you need to get
under a raised vehicle, take it to a service center
where it can be raised on a lift.
•Never start or run the engine while the vehicle is
on a jack.
(Continued)
WARNING!(Continued)
•The jack is designed to be used as a tool for
changing tires only. The jack should not be used to
lift the vehicle for service purposes. The vehicle
should be jacked on a firm level surface only.
Avoid ice or slippery areas.
NOTE:If your vehicle is equipped with an air suspen-
sion system, there is a feature which allows the automatic
leveling to be disabled to assist with changing a tire.
If your vehicle is equipped with a touchscreen, this
feature can be activated through the Uconnect system.
Refer to “Uconnect Settings” in “Understanding Your
Instrument Panel” for further information.
If your vehicle is not equipped with a touchscreen, this
feature can be activated through the Electronic Vehicle
Information Center (EVIC) or Driver Information Display
(DID). Refer to “Electronic Vehicle Information Center
6
WHAT TO DO IN EMERGENCIES 729
Page 732 of 916
(EVIC)” or “Driver Information Display (DID)” in “Un-
derstanding Your Instrument Panel” for further informa-
tion.
Jack Location
The jack and jack tools are stored under the front
passenger seat.
Removal Of Jack And Tools (1500 Series)
To access the jack and jack tools you must remove the
plastic access cover, located on the side of the front
passengers seat. To remove the cover, pull the front part
of the cover (closest to the front of the seat) toward you
to release a locking tab. Once the front of the cover is
loose, slide the cover toward the front of the seat until it
is free from the seat frame.
Jack Access Cover
730 WHAT TO DO IN EMERGENCIES
Page 793 of 916

ONBOARD DIAGNOSTIC SYSTEM (OBD II)
Your vehicle is equipped with a sophisticated onboard
diagnostic system called OBD II. This system monitors
the performance of the emissions, engine, and automatic
transmission control systems. When these systems are
operating properly, your vehicle will provide excellent
performance and fuel economy, as well as engine emis-
sions well within current government regulations.
If any of these systems require service, the OBD II system
will turn on the “Malfunction Indicator Light (MIL).” It
will also store diagnostic codes and other information to
assist your service technician in making repairs. Al-
though your vehicle will usually be drivable and not
need towing, see your authorized dealer for service as
soon as possible.
CAUTION!
•Prolonged driving with the MIL on could cause
further damage to the emission control system. It
could also affect fuel economy and driveability.
The vehicle must be serviced before any emissions
tests can be performed.
•If the MIL is flashing, while the engine is running,
severe catalytic converter damage and power loss
will soon occur. Immediate service is required.
Loose Fuel Filler Cap Message
If the vehicle diagnostic system determines
that the fuel filler cap is loose, improperly
installed, or damaged, a loose gascap indicator
will display in the EVIC/DID telltale display
area. Refer to “Electronic Vehicle Information Center
7
MAINTAINING YOUR VEHICLE 791
Page 794 of 916

(EVIC)” or “Driver Information Display (DID)” in “Un-
derstanding Your Instrument Panel” for further informa-
tion. Tighten the fuel filler cap properly and push the
SELECT button to turn off the message. If the problem
continues, the message will appear the next time the
vehicle is started.
A loose, improperly installed, or damaged fuel filler cap
may also turn on the Malfunction Indicator Light (MIL).
EMISSIONS INSPECTION AND MAINTENANCE
PROGRAMS
In some localities, it may be a legal requirement to pass
an inspection of your vehicle’s emissions control system.
Failure to pass could prevent vehicle registration.
For states that require an Inspection and Mainte-
nance (I/M), this check verifies the “MalfunctionIndicator Light (MIL)” is functioning and is not on when
the engine is running, and that the OBD II system is
ready for testing.
Normally, the OBD II system will be ready. The OBD II
system maynotbe ready if your vehicle was recently
serviced, recently had a dead battery or a battery replace-
ment. If the OBD II system should be determined not
ready for the I/M test, your vehicle may fail the test.
Your vehicle has a simple ignition actuated test, which
you can use prior to going to the test station. To check if
your vehicle’s OBD II system is ready, you must do the
following:
1. Cycle the ignition switch to the ON position, but do
not crank or start the engine.
NOTE:If you crank or start the engine, you will have to
start this test over.
792 MAINTAINING YOUR VEHICLE
Page 830 of 916

transmission fluid level checked. Operating the vehicle
with an improper fluid level can cause severe transmis-
sion damage.
CAUTION!
If a transmission fluid leak occurs, visit your autho-
rized dealer immediately. Severe transmission dam-
age may occur. Your authorized dealer has the proper
tools to adjust the fluid level accurately.
Fluid Level Check — Six-Speed Transmission
It is best to check the fluid level when the transmission is
at normal operating temperature (170-180°F / 77-82°C).
This normally occurs after at least 15 miles (25 km) of
driving. At normal operating temperature the fluid can-
not be held comfortably between the fingertips. You can
read the transmission sump temperature in the EVIC/DID screen (refer to “Electronic Vehicle Information
Center [EVIC]” or “Driver Information Display (DID)”
for further information).
Use the following procedure to check the transmission
fluid level properly:
1. Monitor the transmission temperature using the
EVIC/DID screen, and operate the vehicle as required
to reach the normal operating temperature. If the
transmission is not functioning properly, or the vehicle
cannot be driven, see the NOTE and CAUTION below
about checking the fluid level at colder temperatures.
2. Park the vehicle on level ground.
3. Run the engine at normal idle speed for at least 60
seconds, and leave the engine running for the rest of
this procedure.
4. Fully apply the parking brake, and press the brake
pedal.
828 MAINTAINING YOUR VEHICLE
Page 872 of 916

MAINTENANCE SCHEDULE
Your vehicle is equipped with an automatic oil change
indicator system. The oil change indicator system will
remind you that it is time to take your vehicle in for
scheduled maintenance.
Based on engine operation conditions, the oil change
indicator message will illuminate. This means that ser-
vice is required for your vehicle. Operating conditions
such as frequent short-trips, trailer tow, extremely hot or
cold ambient temperatures, and E85 fuel usage will
influence when the “Oil Change Required” message is
displayed. Severe Operating Conditions can cause the
change oil message to illuminate as early as 3,500 miles
(5,600 km) since last reset. Have your vehicle serviced as
soon as possible, within the next 500 miles (805 km).
Your authorized dealer will reset the oil change indicator
message after completing the scheduled oil change. If a
scheduled oil change is performed by someone otherthan your authorized dealer, the message can be reset by
referring to the steps described under “Electronic Vehicle
Information Center (EVIC)” or “Driver Information Dis-
play (DID)” in “Understanding Your Instrument Panel”
for further information.
1500 Models Only
NOTE:Under no circumstances should oil change inter-
vals exceed 10,000 miles (16,000 km), twelve months or
350 hours of engine run time, whichever comes first. The
350 hours of engine run or idle time is generally only a
concern for fleet customers.
2500 – 3500 Models Only
NOTE:Under no circumstances should oil change inter-
vals exceed 8,000 miles (13,000 km), twelve months or 350
hours of engine run time, whichever comes first. The 350
hours of engine run or idle time is generally only a
concern for fleet customers.
870 MAINTENANCE SCHEDULES