2008 JEEP GRAND CHEROKEE tow and haul

The gauge pointer will likely indicate a higher tempera-
ture when driving in hot weather, up mountain grades,
or when towing a trailer. It should not be allowed to
exceed the upper limits of the normal operating range.
CAUTION!
Driving with a hot engine cooling system could
damage your vehicle. If temperature gauge reads (H),
pull over and stop the vehicle. Idle the vehicle with
the air conditioner turned off until the pointer drops
back into the normal range. If the pointer remains on
the ªHº, and you hear continuous chimes, turn the
engine off immediately, and call for service.
WARNING!
A hot engine cooling system is dangerous. You or
others could be badly burned by steam or boiling
coolant. If you decide to look under the hood your-
self, refer to Section 7 of this manual. Follow the
warnings under ªCooling System Pressure Cap.º
14. Electronic Vehicle Information Center Display
When the appropriate conditions exist, this display
shows the Electronic Vehicle Information Center (EVIC)
messages. Refer to ªElectronic Vehicle Information Cen-
terº later in this section.
15. TOW/HAUL Indicator Light Ð If Equipped
This light will illuminate when the TOW/
HAUL button has been selected. The TOW/
HAUL button is located in the center of the
instrument panel (below the climate controls).
UNDERSTANDING YOUR INSTRUMENT PANEL 193
4

If you are in D (Drive) and are in 5th gear, the first tap to
the left (-) will display 5. Another tap to the left (-) will
shift the transmission into 4th gear.
On vehicles equipped with 4.7L or 5.7L engines, use of
ERS (or Tow/Haul mode) also enables a additional
underdrive gear which is not normally used during
through-gear accelerations. This additional gear im-
proves vehicle performance and cooling capability when
towing a trailer on certain grades. In ERS mode (on all
transmissions), 1st through 3rd gear are underdrive gears
and 4th gear is direct drive. ERS 5th gear (Overdrive) is
the same as the normal 4th gear.
WARNING!
Do not downshift for additional engine braking on a
slippery surface. The drive wheels could lose their
grip and the vehicle could skid.
Screen Display12345*D
Actual Gear(s)
Allowed1 1-2 1-3 1-4 1-5 1-5
* Applies to vehicles equipped with 4.7L/5.7L engines
only.
NOTE:To select the proper gear position for maximum
deceleration (engine braking), move the shift lever to the
left ªD(-)º and hold it there. The transmission will shift to
the range from which the vehicle can best be slowed
down.
Overdrive Operation
The automatic transmission includes an electronically
controlled Overdrive (5th gear for 3.7L engine, 4th and
5th gears for 4.7L and 5.7L engines). The transmission
will automatically shift from direct gear to Overdrive if
the following conditions are present:
288 STARTING AND OPERATING

²the transmission selector is in D (Drive);
²the engine coolant has reached normal operating tem-
perature;
²vehicle speed is above approximately 30 mph (48
km/h);
²the ªTOW/HAULº switch has not been activated;
²transmission has reached normal operating tempera-
ture.
NOTE:If the vehicle is started in extremely cold tem-
peratures, the transmission may not shift into Overdrive
and will automatically select the most desirable gear for
operation at this temperature. Normal operation will
resume when the transmission fluid temperature has
risen to a suitable level. Refer also to the Note under
torque converter clutch, later in this section.During cold temperature operation you may notice de-
layed upshifts depending on engine and transmission
temperature. This feature improves the warm up time of
the engine and transmission.
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 ªTRANSMISSION
OVER TEMPº message may display and the transmis-
sion may downshift out of Overdrive until the transmis-
sion cools down. After cool down, the transmission will
resume normal operation.
In high ambient temperatures with sustained high engine
speed and load, an upshift followed shortly thereafter by
a downshift may occur. This is a normal part of the
overheat protection strategy when operating in the
ªTow/Haulº mode.
STARTING AND OPERATING 289
5

The transmission will downshift from Overdrive to the
most desirable gear if the accelerator pedal is fully
depressed at vehicle speeds above approximately 35 mph
(56 km/h).
When To Use ªTOW/HAULº Mode Ð If Equipped
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the ªTOW/HAULº switch. This will improve
performance and reduce the potential for transmission
overheating or failure due to excessive shifting. When
operating in ªTOW/HAULº mode, the transmission will
shift to direct gear and Overdrive will be enabled under
steady cruise conditions.
The ªTOW/HAULº light will illuminate in the instru-
ment cluster to indicate when the switch has been
activated. Pressing the switch a second time restores
normal operation. If the ªTOW/HAULº mode is desired,
the switch must be pressed each time the engine is
started.
TOW/HAUL Switch
290 STARTING AND OPERATING

WARNING!
Improper towing can lead to an injury accident.
Follow these guidelines to make your trailer towing
as safe as possible:
Make certain that the load is secured in the trailer
and will not shift during travel. When trailering
cargo that is not fully secured, dynamic load shifts
can occur that may be difficult for the driver to
control. You could lose control of your vehicle and
have an accident.
²When hauling cargo or towing a trailer, do not over-
load your vehicle or trailer. Overloading can cause a
loss of control, poor performance or damage to brakes,
axle, engine, transmission, steering, suspension, chas-
sis structure or tires.
²Safety chains must always be used between your
vehicle and trailer. Always connect the chains to the
hook retainers of the vehicle hitch. Cross the chains
under the trailer tongue and allow enough slack for
turning corners.
²Vehicles with trailers should not be parked on a grade.
When parking, apply the parking brake on the tow
vehicle. Put the tow vehicle automatic transmission in
P (Park). For four-wheel-drive vehicles, make sure the
transfer case is not in N (Neutral). Always, block or
9chock9the trailer wheels.
²GCWR must not be exceeded.
²Total weight must be distributed between the tow
vehicle and the trailer such that the following four
ratings are not exceeded:
1. GVWR
2. GTW
STARTING AND OPERATING 359
5

Towing Tips Ð Automatic Transmission
The ªDº range can be selected when towing. However, if
frequent shifting occurs while in this range, the ºTow/
Haulº mode (if equipped) or a lower gear range should
be selected.
NOTE:Using the ºTow/Haulº mode (if equipped) or a
lower gear range while operating the vehicle under
heavy operating conditions will improve performance
and extend transmission life by reducing excessive shift-
ing and heat build up. This action will also provide better
engine braking.
The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. Refer to the ªMain-
tenance Scheduleº in Section 8 of this manual for trans-
mission fluid change intervals.
NOTE:Check the automatic transmission fluid level
before towing.
Towing Tips Ð Electronic Speed Control (If
Equipped)
þ
Don't use in hilly terrain or with heavy loads.
þWhen using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
þUse speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips Ð Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
þCity Driving
When stopped for short periods of time, put transmission
in N (Neutral) and increase engine idle speed.
þHighway Driving
Reduce speed.
STARTING AND OPERATING 363
5

Rear Tail............................ 438
Seat Belt Reminder..................... 194
Security Alarm (Theft Alarm).............. 190
Service.............................. 435
Service Engine Soon (Malfunction Indicator) . . . 188
Side Marker.......................... 438
SmartBeams.......................... 125
Tire Pressure Monitoring (TPMS)........... 191
Tow/Haul Indicator.................... 193
Traction Control....................151,190
Turn Signal..................123,128,437,438
Vanity Mirror.......................... 80
Voltage............................. 195
Load Floor, Cargo....................... 176
Loading Vehicle......................... 348
Tires ............................... 314
Locks................................. 28
Automatic Door........................ 29
Child Protection........................ 30Door................................ 28
Power Door........................... 28
Lower Anchors and Tether for CHildren
(LATCH)............................62,63
Lubrication, Body....................... 405
Luggage Rack (Roof Rack)................. 179
Lumbar Support........................ 110
Maintenance Free Battery.................. 401
Maintenance Procedures................... 394
Maintenance Schedule.................444,449
Diesel.............................. 449
Light Duty Schedule ªAº................ 457
Light Duty Schedule ªBº................. 452
Schedule ªAº......................... 457
Schedule ªBº......................... 452
Malfunction Indicator Light (Check Engine) . . 188,391
Manual, Service......................... 464
Memory Feature (Memory Seat)............. 118
480 INDEX

Tip Start.............................. 280
Tire and Loading Information Placard......... 314
Tire Identification Number (TIN)............. 313
Tire Markings.......................... 310
Tire Safety Information.................... 310
Tires ............................70,318,466
Air Pressure.......................... 319
Alignment and Balance.................. 324
Chains.............................. 325
Changing............................ 372
General Information.................... 318
High Speed.......................... 321
Inflation Pressures..................... 319
Jacking............................. 372
Life of Tires.......................... 323
Load Capacity.....................314,315
Pressure Monitor System (TPMS)........... 326
Pressure Warning Light.................. 191
Quality Grading....................... 466Radial.............................. 321
Replacement......................... 323
Rotation............................. 325
Safety............................70,310
Sizes............................... 311
Spare Tire........................... 373
Spinning............................ 321
Tread Wear Indicators................... 322
Wheel Mounting....................... 377
Tongue Weight/Trailer Weight.............. 357
Torque Converter Clutch.................. 291
Tow Hooks, Emergency................... 381
Tow/Haul Indicator Light................. 193
Towing............................351,382
Disabled Vehicle....................... 382
Guide.............................. 355
Recreational.......................... 364
Weight.............................. 355
Traction Control......................... 139
INDEX 487
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