Page 687 of 790

CAUTION!(Continued)
•Your vehicle has been built with improved fluids
that protect the performance and durability of your
vehicle and also allow extended maintenance inter-
vals. Do not use chemical flushes in these compo-
nents as the chemicals can damage your engine,
transmission, power steering or air conditioning.
Such damage is not covered by the New Vehicle
Limited Warranty. If a flush is needed because of
component malfunction, use only the specified
fluid for the flushing procedure.
Engine Oil
Checking Oil Level
To assure proper lubrication of your vehicle’s engine, the
engine oil must be maintained at the correct level. Check
the oil level at regular intervals, such as every fuel stop. The best time to check the engine oil level is about five
minutes after a fully warmed up engine is shut off.
Checking the oil while the vehicle is on level ground will
improve the accuracy of the oil level readings. Always
maintain the oil level within the SAFE zone on the
dipstick. Adding one quart of oil when the reading is at
the bottom of the SAFE zone will result in a reading at the
top of the safe zone on these engines.
CAUTION!
Overfilling or underfilling the crankcase will cause
oil aeration or loss of oil pressure. This could damage
your engine.
7
MAINTAINING YOUR VEHICLE 685
Page 698 of 790

Under normal operating conditions, the catalytic con-
verter will not require maintenance. However, it is im-
portant to keep the engine properly tuned to assure
proper catalyst operation and prevent possible catalyst
damage.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
In unusual situations involving grossly malfunctioning
engine operation, a scorching odor may suggest severe
and abnormal catalyst overheating. If this occurs, stop
the vehicle, turn off the engine and allow it to cool.
Service, including a tune-up to manufacturer’s specifica-
tions, should be obtained immediately. To minimize the possibility of catalytic converter dam-
age:
•
Do not shut off the engine or interrupt the ignition,
when the transmission is in gear and the vehicle is in
motion.
• Do not try to start the engine by pushing or towing the
vehicle.
• Do not idle the engine with any spark plug wires
disconnected or removed, such as when diagnostic
testing, or for prolonged periods during very rough
idle or malfunctioning operating conditions.
696 MAINTAINING YOUR VEHICLE
Page 710 of 790

NOTE:When refilling an axle with a Limited Slip Differ-
ential, (which requires a Limited Slip Additive), the
Limited Slip Additive should be added before the gear
lubricant is added to insure proper additive fill.
Transfer Case
Drain And Refill
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
Lubricant Selection
Refer to “Fluids, Lubricants, and Genuine Parts” in
“Maintaining Your Vehicle” for further information.
Fluid Level Check
This fluid level can be checked by removing the filler
plug. The fluid level should be to the bottom edge of the
filler plug hole with the vehicle in a level position.
Automatic Transmission
Selection Of Lubricant
It is important to use the proper transmission fluid to
ensure optimum transmission performance and life. Use
only the manufacturer ’s specified transmission fluid.
Refer to “Fluids, Lubricants, and Genuine Parts” in this
section for fluid specifications. It is important to maintain
the transmission fluid at the correct level using the
recommended fluid. No chemical flushes should be used
in any transmission; only the approved lubricant should
be used.
CAUTION!
Using a transmission fluid other than the manufac-
turer ’s recommended fluid may cause deterioration
in transmission shift quality and/or torque converter
(Continued)
708 MAINTAINING YOUR VEHICLE
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CAUTION!(Continued)
shudder, and will require more frequent fluid and
filter changes. Refer to “Fluids, Lubricants, and
Genuine Parts” in this section for fluid specifica-
tions.
Special Additives
The manufacturer strongly recommends against using
any special additives in the transmission. Automatic
Transmission Fluid (ATF) is an engineered product and
its performance may be impaired by supplemental addi-
tives. Therefore, do not add any fluid additives to the
transmission. The only exception to this policy is the use
of special dyes for diagnosing fluid leaks. Avoid using
transmission sealers as they may adversely affect seals.
CAUTION!
Do not use chemical flushes in your transmission as
the chemicals can damage your transmission compo-
nents. Such damage is not covered by the New
Vehicle Limited Warranty.
Fluid Level Check — Eight-Speed Transmission
The fluid level is preset at the factory and does not require
adjustment under normal operating conditions. Routine
fluid level checks are not required, therefore the transmis-
sion has no dipstick. Your authorized dealer can check your
transmission fluid level using special service tools.
If you notice fluid leakage or transmission malfunction,
visit your authorized dealer immediately to have the
transmission fluid level checked. Operating the vehicle
with an improper fluid level can cause severe transmis-
sion damage.7
MAINTAINING YOUR VEHICLE 709
Page 712 of 790

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
display (refer to “Electronic Vehicle Information Center
[EVIC]” for further information).Use the following procedure to check the transmission
fluid level properly:
1. Monitor the transmission temperature using the EVIC
display, and operate the vehicle as required to reach
the normal operating temperature.
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.
5.
Place the shift lever momentarily into each gear position
(allowing time for the transmission to fully engage in
each position), ending with the transmission in PARK.
6. Remove the dipstick, wipe it clean and reinsert it until seated.
710 MAINTAINING YOUR VEHICLE
Page 713 of 790

7. Remove the dipstick again and note the fluid level onboth sides. The fluid level reading is only valid if there
is a solid coating of oil on both sides of the dipstick.
Note that the holes in the dipstick will be full of fluid
if the actual level is at or above the hole. The fluid level
should be between the “HOT” (upper) reference holes
on the dipstick at normal operating temperature. If the
fluid level is low, add fluid through the dipstick tube
to bring it to the proper level. Do not overfill.Use
ONLY the recommended fluid (see Fluids, Lubri-
cants, and Genuine Parts for fluid specifications).
After adding any quantity of oil through the dipstick
tube, wait a minimum of two minutes for the oil to
fully drain into the transmission before rechecking the
fluid level. NOTE:
If it is necessary to check the transmission below
the operating temperature, the fluid level should be
between the two “COLD” (lower) holes on the dipstick
with the fluid at 60-70°F / 16-21°C. Only use the COLD
region of the dipstick as a rough reference when setting
the fluid level after a transmission service or fluid
change. Re-check the fluid level, and adjust as required,
once the transmission reaches normal operating tempera-
ture.
CAUTION!
If the fluid temperature is below 50°F (10°C) it may
not register on the dipstick. Do not add fluid until
the temperature is elevated enough to produce an
accurate reading. Run the engine at idle, in PARK, to
warm the fluid.
8. Check for leaks. Release the parking brake.
7
MAINTAINING YOUR VEHICLE 711
Page 714 of 790

NOTE:To prevent dirt and water from entering the
transmission after checking or replenishing fluid, make
sure that the dipstick cap is properly reseated. It is
normal for the dipstick cap to spring back slightly from
its fully seated position, as long as its seal remains
engaged in the dipstick tube.
Fluid And Filter Changes — Eight-Speed
Transmission
Under normal operating conditions, the fluid installed at
the factory will provide satisfactory lubrication for the
life of the vehicle.
Routine fluid and filter changes are not required. How-
ever change the fluid and filter if the fluid becomes
contaminated (with water, etc.), or if the transmission is
disassembled for any reason.
Fluid And Filter Changes — Six-Speed
Transmission
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
In addition, change the fluid and filter(s) if the fluid
becomes contaminated (with water, etc.), or if the trans-
mission is disassembled for any reason.
Appearance Care And Protection From Corrosion
Protection Of Body And Paint From Corrosion
Vehicle body care requirements vary according to geo-
graphic locations and usage. Chemicals that make roads
passable in snow and ice and those that are sprayed on
trees and road surfaces during other seasons are highly
corrosive to the metal in your vehicle. Outside parking,
which exposes your vehicle to airborne contaminants,
road surfaces on which the vehicle is operated, extreme
712 MAINTAINING YOUR VEHICLE
Page 727 of 790
Cavity Cartridge Fuse Micro FuseDescription
F50 20 Amp Yellow Air Suspension Control Module – If Equipped
F51 10 Amp RedIgnition Node Module / Keyless Ignition
F52 5 Amp Tan Battery Sensor
F53 20 Amp YellowTrailer Tow – Left Turn/Stop Lights
F54 20 Amp Yellow Adjustable Pedals
F55 20 Amp Yellow E38 Radio – If Equipped
F56 15 Amp BlueAdditional Diesel Content – If Equipped
F57 20 Amp Yellow Transmission
F58 20 Amp Yellow
(Gas Engine) / 25 Amp Natural
(Cummins Diesel Engine) Engine Cooling Pump
F60 15 Amp Blue Underhood Lamp
F61 20 Amp YellowPower Take-off Unit – If Equipped
7
MAINTAINING YOUR VEHICLE 725