Page 72 of 173

gear (when climbing a grade), or shifting to NEUTRAL
(when stopped in heavy traffic) can help to reduce this
excess heat generation.
During cold temperatures, transmission operation may
be modified depending on engine and transmission
temperature as well as vehicle speed. This feature im-
proves warm up time of the engine and transmission to
achieve maximum efficiency. Engagement of the torque
converter clutch is inhibited until the transmission fluid
is warm (refer to the “Note” under “Torque Converter
Clutch” in this section). On cold starts below 41°F (5°C),
fifth and sixth gears may be inhibited briefly. During very
cold temperatures (-4°F [-20°C] or below), operation may
briefly be limited to third gear only. During this condi-
tion, the ability of the vehicle to accelerate under heavily
loaded conditions may be reduced. Normal operation
will resume once the transmission temperature has risen
to a suitable level.Transmission Limp Home Mode
Transmission function is monitored electronically for
abnormal conditions. If a condition is detected that could
result in transmission damage, Transmission Limp Home
Mode is activated. In this mode, the transmission remains
in third gear regardless of which forward gear is selected.
If the vehicle enters Limp Home Mode at highway
speeds, it will initially engage fifth gear, until the vehicle
slows to a speed where third gear can be engaged. PARK,
REVERSE, and NEUTRAL will continue to operate. Limp
Home Mode allows the vehicle to be driven to an
authorized dealer for service without damaging the
transmission.
In the event of a momentary problem, the transmission
can be reset to regain all forward gears by performing the
following steps:
1. Stop the vehicle.
70 STARTING AND OPERATING
Page 76 of 173

WARNING!
Do not use the “TOW/HAUL” feature when driving
in icy or slippery conditions. The increased engine
braking can cause the rear wheels to slide, and the
vehicle to swing around with the possible loss of
vehicle control, which could cause an accident possi-
bly resulting in personal injury or death.
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
the upper gears. When the vehicle speed drops or during
some accelerations, the clutch automatically disengages.NOTE:
•The torque converter clutch will not engage until the
transmission fluid and engine coolant are warm [usu-
ally after 1 to 3 miles (1.6 to 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. Using the Electronic Range Select (ERS)
feature, when the transmission is sufficiently warm,
will demonstrate that the transmission is able to shift
into and out of Overdrive.
•If the vehicle has not been driven for several days, the
first few seconds of operation after shifting the trans-
mission 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
cause damage to the transmission. The torque con-
verter will refill within five seconds after starting the
engine.
74 STARTING AND OPERATING
Page 80 of 173

Reverse Shifting
To shift into REVERSE (R), bring the vehicle to a com-
plete stop. Press the clutch and pause briefly to allow the
gear train to stop rotating. Beginning from the NEUTRAL
(N) position, move the shift lever in one quick smooth
motion straight across and into the REVERSE (R) area
(the driver will feel a firm “click” as the shifter passes the
“knock-over”). Complete the shift by pulling the shift
lever into REVERSE (R).
The “knock-over” prevents the driver from accidentally
entering the REVERSE (R) shift area and warns the driver
that they are about to shift the transmission into RE-
VERSE (R). Due to this feature, a slow shift to REVERSE
(R) can be perceived as a high shift effort.
To shift out of REVERSE bring the vehicle to a complete
stop and press the clutch. Shifting out of REVERSE prior
to a complete stop may cause high shift effort.
POWER TAKE OFF OPERATION — IF EQUIPPED
(CHASSIS CAB ONLY)
This vehicle when equipped with either the AS68RC
automatic six-speed or G-56 manual six-speed transmis-
sions, will allow for an aftermarket upfit with a transmis-
sion driven PTO (power take off). The customer will have
the ability to operate the PTO in either a “stationary” or
“mobile” mode. The vehicles will be factory set to the
“stationary” mode. In order to select the “mobile” mode
an authorized dealership is required to modify the vehi-
cle’s settings using their proprietary authorized dealer
service tool.
AS68RC Six-Speed Automatic Transmission Only
The PTO drive gear (part of the AS68RC) operates at
torque converter turbine speed. The turbine speed will be
less than engine speed when the torque converter clutch
is not engaged and will be same as engine speed when
the torque converter clutch is engaged.
78 STARTING AND OPERATING
Page 81 of 173

Stationary Mode
To operate the PTO in this mode the vehicle must meet
the following conditions:
•Be in PARK position (vehicles equipped with auto-
matic transmission)
•Upfitter provider (on/off) switch has been activated
•Parking brake applied (vehicles equipped with
manual transmission)
•Brake pedal must not be applied
•Vehicle engine must be running
•No vehicle, brake or clutch switch faults present
•PTO must be correctly installed using the vehicle
provided circuits
The customer has the choice to operate the PTO by
utilizing the cruise control switches or by utilizing a remote control (provided by the PTO supplier). To oper-
ate the feature using the cruise control switches, the
customer must first activate the upfitter-provided on/off
switch which will turn on the PTO. In order to increase or
decrease the engine idle speed, to optimize the PTO
function, the “RESUME/ACCEL” and “DECEL” cruise
switches can be used respectively. To disengage PTO
operation and return to “standard vehicle operation”
simply turn the upfitter-provided on/off switch to the
OFF position.
The torque converter lockup clutch will automatically
engage at engine speeds above 1,200 RPM (engine speed)
in PTO stationary mode. Once engaged, the lockup clutch
will remain on and not disengage until the engine speed
is below 1,000 RPM. Lockup clutch engagement is desir-
able for certain types of PTO applications (AS68RC
Six-Speed Automatic Transmission Only).
4
STARTING AND OPERATING 79
Page 91 of 173
The DEF injection system and SCR catalyst enable the
achievement of diesel emissions requirements; while
maintaining outstanding fuel economy, drivability,
torque and power ratings.
Refer to “Electronic Vehicle Information Center
(EVIC)” in “Understanding Your Instrument Panel” for
system messages and warnings.NOTE:
The DEF pump will run for a period of time
after engine shutdown to purge the DEF system. This is
normal operation.
4
STARTING AND OPERATING 89
Page 171 of 173

Signals, Turn............................ 15
Speedometer ............................ 16
Starting .............................. 8,34
Automatic Transmission ................ 34
Engine Block Heater ................. 35,49
Manual Transmission .................. 34
Remote ............................. 8
Starting Procedures ....................... 34
Starting Procedures (Diesel Engines) ........... 34
Steering Wheel Lock .......................... 8
Synthetic Engine Oil ...................... 104
System, Remote Starting .................... 8
Tachometer ............................. 15
Temperature Gauge, Engine Coolant ........... 15
Tip Start ............................... 34
Ti re s Pressure Warning Light ................. 21 Torque Converter Clutch
.................63,74
Tow/Haul ............................. 62
Traction Control ......................... 123
Traction Control Light ..................... 17
Transfer Case Fluid ............................. 136
Transmission Automatic ........................ 54,64
Fluid ............................. 136
Manual .......................... 34,75
Shifting ............................ 52
Trip Odometer ........................ 17,18
Turn Signals ............................ 15
Viscosity, Engine Oil ...................... 103
Voltmeter ............................ 18,41
Warning Lights (Instrument Cluster Description) . . 15
Water Separator, Diesel Fuel ................ 106
8
INDEX 169