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NOperating Precautions..................268
NCooling System Tips Ð Automatic
Transmission........................268
mEngine Block Heater (Gas Engines)Ð
If Equipped...........................270
mDiesel Exhaust Brake (Engine Braking) ±
If Equipped...........................270
mAutomatic Transmission..................273
NAutomatic Transmission With Overdrive
(5 Speed 545RFE) Ð If Equipped..........273
NAutomatic Transmission (6 Speed AS68RC) Ð
If Equipped.........................279
mManual Transmission....................285
NManual Transmission Ð 6 Speed (G56)......286
NRecommended Vehicle Shift Speeds........287NDownshifting ± Gas Engine..............288
NDownshifting ± Diesel Engine............288
mFour-Wheel-Drive Operation Ð If Equipped....289
NManually Shifted Transfer Case Operating
Information/Precautions................289
NShifting Procedure Ð Manually Shifted
Transfer Case........................292
NTransfer Case Reminder Light............293
NElectronically Shifted Transfer Case Operating
Information/Precautions (4 Position Switch) Ð
If Equipped.........................294
NShifting Procedure Ð Electronically Shifted
Transfer Case........................298
mLimited-Slip Differential Ð If Equipped.......301
mPower Take Off Operation ± If Equipped......302
248 STARTING AND OPERATING
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Normal Starting Procedure Ð Engine Manifold Air
Temperature Above 66ÉF (19ÉC)
Observe the Instrument Panel Cluster lights when start-
ing the engine.
1. Always apply the parking brake.
2. Shift into PARK for an automatic transmission. Fully
depress and hold the clutch and shift into NEUTRAL for
a manual transmission. Models with manual transmis-
sion are equipped with a clutch interlocking cranking
system. The clutch must be fully depressed to start the
vehicle.
3. Turn the ignition key to the ON position and look at
the instrument panel cluster lamps.
CAUTION!
If WATER IN FUEL indicator light remains on DO
NOT START engine before you drain water from the
fuel filter to avoid engine damage. See Section 7 Ð
Maintaining Your Vehicle, for water drain
procedures.
4. Turn the ignition key to START and crank the engine.
Do not press the accelerator during starting.
CAUTION!
Do not crank engine for more than 15 seconds at a
time as starter motor damage may result. Turn key to
OFF and wait at least two minutes before trying
again.
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5. When the engine starts, release the key.
6. Check to see that there is oil pressure.
7. Release the parking brake.
Starting Procedure Ð Engine Manifold Air
Temperature Below 66ÉF (19ÉC)
NOTE:The temperature displayed on the overhead
console (if equipped) does not necessarily reflect the
engine manifold air temperature. When certain engine
temperatures fall below 66ÉF (19ÉC) the lamp will remain
on indicating the intake manifold heater system is active.
Follow the steps in the Normal Starting Procedure ex-
cept:
CAUTION!
Do not crank engine for more than 15 seconds at a
time or starter motor damage may result. Turn key to
OFF and wait at least 2 minutes for starter to cool
before repeating start procedure.
²The WAIT TO START light will remain on for a period
of time (length of time depends on engine tempera-
ture).
²After the WAIT TO START light goes off, turn the
ignition key to START. Do not press the accelerator
during starting.
²After engine start-up, check to see that there is oil
pressure.
258 STARTING AND OPERATING
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²Allow the engine to idle about three minutes until
the manifold heaters have completed the post-heat
cycle.
²Release the parking brake and drive.
NOTE:Engine idle speed will automatically increase to
1000 rpm at low coolant temperatures to improve engine
warm-up.
NOTE:If the engine stalls or if the ignition switch is left
On for more than 2 minutes after the WAIT TO START
light goes out, reset the grid heaters by turning the
ignition switch to Off for at least 5 seconds and then back
On. Repeat steps 3 through 7 of the normal starting
procedure.
For Extremely Cold Weather Starting Ð Engine
Manifold Air Temperature Below 0ÉF (- 18ÉC)
In extremely cold weather below 0ÉF (- 18ÉC) it may be
beneficial to cycle the manifold heaters twice before
attempting to start the engine. This can be accomplished
by turning the ignition OFF for at least 5 seconds and
then back ON after the WAIT TO START light has gone
off, but before the engine is started. However, repeated
cycling of the manifold heaters will result in damage to
the heater elements or reduced battery voltage.
NOTE: If multiple pre-heat cycles are used before
starting, additional engine run time may be required to
maintain battery state of charge at a satisfactory level.
²If the engine stalls after the initial start, the ignition
must be turned to the OFF position for at least 5
seconds and then to the ON position to recycle the
manifold heaters.
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NOTE:Excessive white smoke and poor engine perfor-
mance will result if manifold heaters are not recycled.
²Heat generated by the manifold heaters dissipates
rapidly in a cold engine. If more than two minutes
pass between the time the WAIT TO START light goes
OFF and the engine is started, recycle the manifold
heaters by turning the ignition OFF for at least 5
seconds and then back ON.
²If the vehicle is driven and vehicle speed exceeds 19
mph (31 km) before the manifold heater post-heat
(after start) cycle is complete, the manifold heaters will
shut off.
²If the engine is started before the WAIT TO START
light turns off, the preheat cycle will turn off.
²If the engine is cranked for more than 10 seconds, the
post-heat cycle will turn off.NOTE:Engine idle speed will automatically increase to
1000 rpm at low coolant temperatures to improve engine
warm-up.
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.
260 STARTING AND OPERATING
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WARNING!
Do not leave children or animals inside parked
vehicles in hot weather. Interior heat build up may
cause serious injury or death.
NORMAL OPERATION ± DIESEL ENGINE
Observe the following when the engine is operating.
²All message center lights are off.
²Check Engine Lamp is off.
²Engine Oil Pressure is above 10 psi (69 kPa) at idle.
²Low Oil Pressure light is off.
²Voltmeter Operation:
²The voltmeter may show a gauge fluctuation at
various engine temperatures. This cycling operation
is caused by the post-heat cycle of the intake mani-
fold heater system. The number of cycles and the
length of the cycling operation is controlled by the
engine control module. Post-heat operation can run
for several minutes, and then the electrical system
and voltmeter needle will stabilize.
²The cycling action will cause temporary dimming of
the headlamps, interior lamps, and also a noticeable
reduction in blower motor speed.
262 STARTING AND OPERATING
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If the transmission temperature gets extremely hot, the
transmission will automatically select the most desirable
gear for operation at this temperature. If the transmission
temperature becomes hot enough the TRANS TEMP light
may illuminate and the transmission may downshift out
of Overdrive until the transmission cools down. After
cooldown, the transmission will resume normal opera-
tion.
The transmission will downshift from Overdrive to Drive
if the accelerator pedal is fully depressed at vehicle
speeds above approximately 35 mph (56 km/h).When To Use ªTOW HAULº and ªO/D OFFº
Modes
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the ªTOW HAUL O/D OFFº button once to
select TOW HAUL. This will improve performance and
Tow Haul O/D Off Switch
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reduce the potential for transmission overheating or
failure due to excessive shifting. When operating in
ªTOW HAULº mode, 5th gear is disabled and 2-3 and 3-4
shift patterns are modified. Shifts into Overdrive (4th
gear) are allowed during steady cruise (for improved fuel
economy) and automatic closed-throttle downshifts to
3rd gear (for improved braking) will occur during steady
braking. Pressing the ªTOW HAUL O/D OFFº button a
second time to select O/D OFF will disable 4th and 5th
gear completely, which should eliminate any excessive
transmission shifting.
The ªTOW HAULº or ªO/D OFFº light will illuminate in
the instrument cluster to indicate when the switch has
been activated. Pressing the switch a third time restores
normal operation. If the ªTOW HAULº or ªO/D OFFº
modes are desired, the button must be pressed each time
the engine is started.When To Lock Out Overdrive
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent 4±3±4 transmission shifting
occurs, press the ªTOW/HAULº button twice to disable
the overdrive. This will improve performance and reduce
the potential for transmission overheating or failure due
to excessive shifting.
Torque Converter Clutch
A feature, designed to improve fuel economy, has been
included in the automatic transmission on your vehicle.
A clutch within the torque converter engages automati-
cally at calibrated speeds. This may result in a slightly
different feeling or response during normal operation in
high gear. When the vehicle speed drops or during
acceleration when the transmission downshifts to second
gear, the clutch automatically disengages.
278 STARTING AND OPERATING