2006 JEEP GRAND CHEROKEE transmission

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“TRANSMISSIONOVER TEMP”message may display and the transmis-
sion may downshift out of Overdrive until the transmis-
sion cools down. After cooldown, 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
“Tow/Haul”mode.
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“TOW/HAUL”Mode—If Equipped
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the“TOW/HAUL”button. This will improve
performance and reduce the potential for transmission
258 STARTING AND OPERATING

overheating or failure due to excessive shifting. When
operating in“TOW/HAUL”mode, the transmission will
shift to 3rd gear and 4th will be enabled under steady
cruise conditions.
The“TOW/HAUL”light will illuminate in the instru-
ment cluster to indicate when the switch has beenactivated. Pressing the switch a second time restores
normal operation. If the“TOW/HAUL”mode is desired,
the switch must be pressed each time the engine is
started.
Transmission Limp Home Mode
Transmission function is monitored for abnormal condi-
tions. If a condition is detected that could result in
transmission damage, the transmission limp home mode
will be engaged. In this mode, the transmission will
remain in the current gear until the vehicle is brought to
a stop.
To reset the transmission, use the following procedure:
1. Stop the vehicle.
2. Move the shift lever to the P (Park) position.
3. Turn off the engine, be sure to turn the key to the
LOCK position.
Tow/Haul Button
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5

4. Wait approximately 10 seconds, then restart the en-
gine.
5. Move the shift lever to the desired gear range.
If the problem is no longer detected, the transmission will
return to normal operation. If the problem persists, P
(Park), R (Reverse), and N (Neutral) will continue to
operate. Only Second gear range will operate in the D
(Drive) shifter position. Have the transmission checked at
your authorized dealer as soon as possible.
Torque Converter Clutch
A feature designed to improve fuel economy is included
in all automatic transmissions. A clutch within the torque
converter engages automatically at a calibrated speed at
light throttle. It engages at higher speeds under heavier
acceleration. This may result in a slightly different feeling
or response during normal operation in high gear. When
the vehicle speed drops below a calibrated speed, orduring acceleration, the clutch automatically and
smoothly disengages. The feature is operational in Over-
drive and in Drive.
NOTE:The torque converter clutch will not engage
until the transmission fluid and engine coolant are warm
[usually after 1-3 miles (1.6 - 4.8 km) of driving]. Because
the engine speed is higher when the torque converter
clutch is not engaged, it may seem as if the transmission
is not shifting into Overdrive when cold. This is normal.
Manually shifting between 3 (third gear) and 4 (fourth
gear) positions (using the ERS shift control) will demon-
strate that the transmission is able to shift into and out of
Overdrive.
NOTE:If the vehicle has not been driven in several
days, the first few seconds of operation after shifting the
transmission into gear may seem sluggish. This is due to
the fluid partially draining from the torque converter into
the transmission. This condition is normal and will not
260 STARTING AND OPERATING

cause damage to the transmission. The torque converter
will refill within five seconds of shifting from Park into
any other gear position.
Rocking the Vehicle
If the vehicle becomes stuck in snow, sand, or mud, it can
often be moved by a rocking motion. Move the gear
selector rhythmically between D (Drive) and R (Reverse),
while applying slight pressure to the accelerator.
NOTE:The Electronic Stability Program (ESP) and
Traction Control (if equipped) should be turned OFF
before attempting to rock the vehicle. Refer to“Electronic
Brake Control System”in Section 3 of this manual.
The least amount of accelerator pedal pressure to main-
tain the rocking motion without spinning the wheels or
racing the engine is most effective. Racing the engine or
spinning the wheels, due to the frustration of not freeing
the vehicle, may lead to transmission overheating and
failure. Allow the engine to idle with the transmissionselector in N (Neutral) for at least one minute after every
five rocking-motion cycles. This will minimize overheat-
ing and reduce the risk of transmission failure during
prolonged efforts to free a stuck vehicle.
CAUTION!
When“rocking”a stuck vehicle by moving between
“First”and R (Reverse), do not spin the wheels faster
than 15 mph (24 km/h), or drivetrain damage may
result.
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5

road surfaces only. Driving in the 4 LOW position on dry
hard surfaced roads may cause increased tire wear and
damage to driveline components.
When operating your vehicle in 4 LOW, the engine speed
is approximately three times that of the 4 HI position at a
given road speed. Take care not to overspeed the engine
and do not exceed 25 mph (40 km/h).
Proper operation of four wheel drive vehicles depends on
tires of equal size, type, and circumference on each
wheel. Any difference will adversely affect shifting and
cause damage to the transfer case.
Because four wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.WARNING!
You or others could be injured if you leave the
vehicle unattended with the transfer case in the N
(Neutral) position without first fully engaging the
parking brake. The transfer case N (Neutral) position
disengages both the front and rear driveshafts from
the powertrain and will allow the vehicle to move
regardless of the transmission position. The parking
brake should always be applied when the driver is
not in the vehicle.
Shift Positions
For additional information on the appropriate use of each
transfer case mode position, see the information below:
4HI
Four Wheel Drive High Range—All roads surfaces such
as ice, snow, gravel, sand, and dry hard pavement.
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5

N (Neutral)
Neutral—Disengages both the front and rear driveshafts
from the powertrain. To be used for flat towing behind
another vehicle. Refer to“Recreational Towing”in Sec-
tion 5 of this manual.
4 LOW
Four Wheel Drive Low Range—Low speed 4 wheel
drive. Locks the front and rear driveshafts together.
Forces the front and rear wheels to rotate at the same
speed. Additional traction and maximum pulling power
for loose, slippery road surfaces only. Do not exceed 25
mph (40 km/h).
Shifting Procedures
4HIto4LOW
With the vehicle at speeds of 0 to 3 mph (0 to 5 km/h),
key ON or engine running, shift the transmission into N
(Neutral), and raise the transfer case T-handle.“The 4WD
LOW Indicator Lamp”in the instrument cluster will
begin to flash and remain on solid when the shift is
complete. Release the T-handle.
NOTE:If shift conditions/interlocks are not met, or a
transfer case motor temperature protection condition
exists, a“CHECK SHIFT PROCEDURES”message will
flash from the EVIC (Electronic Vehicle Information Cen-
ter). Refer to“Electronic Vehicle Information Center
(EVIC)”in Section 4 of this manual. (See page 187 for
more information.)
264 STARTING AND OPERATING

4 LOW to 4 HI
With the vehicle at speeds of 0 to 3 mph (0 to 5 km/h),
key ON or engine running, shift the transmission into N
(Neutral), and raise the transfer case T-handle. The“4WDLOW Indicator Lamp”in the instrument cluster will flash
and go out when the shift is complete. Release the
T-handle.
NOTE:If shift conditions/interlocks are not met, or a
transfer case motor temperature protection condition
exists, a“CHECK SHIFT PROCEDURES”message will
flash from the EVIC (Electronic Vehicle Information Cen-
ter). Refer to“Electronic Vehicle Information Center
(EVIC)”in Section 4 of this manual. (See page 187 for
more information.)
NOTE:Shifting into or out of 4WD LOW is possible
with the vehicle completely stopped, however difficulty
may occur due to the mating clutch teeth not being
properly aligned. Several attempts may be required for
clutch teeth alignment and shift completion to occur. The
preferred method is with the vehicle rolling 0 to 3 mph (0
to 5 km/h). If the vehicle is moving faster than 3 mph (5
km/h), the transfer case will not allow the shift.
Shifter T-Handle
STARTING AND OPERATING 265
5

Neutral (N) Shift Procedure
1. Key ON, engine off.
2. Vehicle stopped, with foot on brake.
3. Place transmission in N (Neutral).
4. Hold down N (Neutral)“pin”switch (with a pen, etc.)
for 4 seconds until the LED lamp by the switch starts to
blink indicating shift in progress. Lamp will stop blinking
(stay on solid) when Neutral shift is complete. A“4WD
SYSTEM IN NEUTRAL”message will display on the
EVIC (Electronic Vehicle Information Center). Refer to
“Electronic Vehicle Information Center (EVIC)”in Sec-
tion 4 of this manual. (See page 187 for more informa-
tion.)5. Repeat Steps 1–4 to shift out of Neutral.
Neutral Switch
266 STARTING AND OPERATING