Exhaust Restrictor (Engine
Warm-Up)
Exhaust Restrictor
If the vehicle has a Isuzu 6H Diesel Engine, it may have
a feature called an Exhaust Restrictor (NPE), which
uses an air actuated valve in the exhaust system
to restrict exhaust gas flow which enhances the engine
and heater warm-up.
Automatic Quick Warm-Up
If the vehicle has a DURAMAX®6600 engine, it has a
feature called an Automatic Quick Warm-Up, which uses
the turbocharger to restrict the exhaust gas flow
which enhances the engine and heater warm-up.
In both systems, exhaust restrictor or automatic quick
warm-up, the cold temperature high idle feature elevates
the engines idle speed, up to 1500 rpm, and restricts
the exhaust gas flow, when outside temperatures
are below 50°F (10°C), and the engine coolant
temperature is below certain levels. This feature
enhances heater performance by raising the engine
coolant temperature faster.For all engines this feature is already turned on. The
automatic quick warm-up on the DURAMAX
®engine
can be turned off and on by doing the following
procedure:
1. Turn the ignition to ON/RUN, with the vehicle off.
2. Press the accelerator pedal to the floor and
hold it while quickly pressing and fully releasing the
brake pedal three times in less than eight seconds.
3. Release the accelerator pedal and start the engine.
The green exhaust brake/restrictor light below the
radio controls will be lit for 10 seconds.
If this feature is turned off, by doing the procedure
described previously, and then the engine is
started, the exhaust brake/restrictor light will flash
for 10 seconds and then it will turn off.
When the engine is started, it will slowly increase to the
high idle speed after a delay of a few seconds; up to
about two minutes. For this method to work properly
there must be no throttle or brake pedal faults, and the
throttle pedal must not fall below 75 percent of wide
open throttle while pressing the brake pedal.
2-22
The engine idle speed will return to normal once the
following conditions are met:
•Once engine coolant temperature reaches about
150°F (65°C).
•The intake temperature reaches a certain level.
The high idle speed will be temporarily interrupted and
the engine speed will return to normal if any of the
following conditions occur:
•The brake pedal is applied.
•The accelerator pedal is pressed.
•The automatic transmission is shifted out of
P (Park) or N (Neutral).
•The clutch pedal on the manual transmission is
pressed.
•Vehicle speed is detected.
Once these conditions no longer exist, the engine idle
speed will slowly increase to high idle after the
normal delay, if the conditions for engine coolant
temperature and air intake temperature are still met.
Engine Checks Before Operating
When you have started the engine, let it run for
20 to 30 seconds before you put a load on the engine.
But do not leave the vehicle while the engine is running.
Avoid unnecessary idling of diesel engine equipped
vehicles.
If the engine idles too long, the temperature of the
engine coolant will fall below the normal operating
range. Low engine operating temperature causes
several conditions which affect engine operation and
reduce engine life.
The engine should be permitted to go through a
warm-up period. Operate the vehicle at a minimum of
600 rpm during the warm-up period. During this
period and during operation, the following observations
should be made.
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Manual Cleaning Procedure
{CAUTION:
During DPF self cleaning, the exhaust system and
exhaust gases are very hot. Stay clear of the
tailpipe area and do not park over things that burn.
You or others could be burned or the vehicle could
catch fire. SeeParking Over Things That Burn on
page 2-44.
If the yellow or red DPF indicator is on, you can clean
the DPF by performing a manual cleaning.When it is safe to do so, stop the vehicle. Perform DPF
manual cleaning in a well ventilated area. DPF Manual
cleaning must be performed outdoors, as follows. Once
manual cleaning is started, complete the manual cleaning
in a single operation if possible. If manual cleaning is not
completed, as indicated by the green DPF indicator going
off, and the yellow or red indicator light remains on, self
cleaning might not be allowed until the vehicle is stopped
and manual cleaning is performed until completed.
1. Check engine oil and engine coolant levels to be
sure they are at proper operating levels.
2. To prevent running out of fuel during manual
cleaning, make sure there is at least a quarter of a
tank of fuel.
3. Check to make sure the area near the exhaust
tailpipe and under the exhaust system are clear
of any materials that could catch fire. Keep people
away from the area of the exhaust system and
exhaust gases.
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4. Fully set the parking brake.
5. Shift the transmission to P (Park) or N (Neutral).
6. Idle the engine. If you used the idling control knob to
increase the engine speed, restore it all the way to
the left to reduce the engine speed.
7. If the vehicle has a Power Take Off (PTO), turn the
PTO off. SeePower Take-Off (PTO) on page 2-30.
8. Press the DPF switch in the instrument panel
switchbank. SeeInstrument Panel Switchbank
on page 3-18. The green DPF indicator light comes
on, the exhaust gas control valve operates,
engine idle speed automatically increases, and DPF
cleaning begins. Do not leave the vehicle
unattended during manual cleaning.9. When both the green and the yellow or red DPF
indicator lights go off, cleaning is completed.
Manual cleaning is normally completed in about
30 minutes.
Under certain operating conditions, manual cleaning
might not be able to be performed, even if the soot level
in the DPF requires cleaning. This can occur because of
low coolant temperature, low battery voltage, high
exhaust temperature or immediately after starting the
vehicle. When manual cleaning is requested and coolant
temperature is low, an engine warm-up cycle is started.
The green indicator light will come on, the exhaust gas
control valve operates, and engine rpm increases to help
raise engine coolant temperature. When operating
conditions allow, cleaning will begin.
2-49
Low Coolant Warning Light............................3-35
Wait to Start Light........................................3-35
Malfunction Indicator Lamp.............................3-36
Oil Pressure Gage........................................3-38
Low Oil Level Light.......................................3-39
Change Engine Oil Light................................3-39
Engine Overspeed Warning Light....................3-40
Engine Shutdown Warning Light.....................3-40
Transmission Temperature Gage.....................3-40
Exhaust Brake Indicator Light.........................3-41
Differential Lock Indicator Light.......................3-41
Reduced Engine Power Light.........................3-42
Highbeam On Light.......................................3-42
Daytime Running Lamps (DRL)
Indicator Light...........................................3-42
Low Washer Fluid Warning Light.....................3-43
Power Take-Off Light (PTO)...........................3-43Check Gages Warning Light...........................3-43
Fuel Gage...................................................3-44
Water in Fuel Warning Light...........................3-45
Change Fuel Filter Warning Light....................3-45
Diesel Particulate Filter Warning Light..............3-46
Air Filter Restriction Indicator..........................3-46
Air Pressure Gage........................................3-47
Hourmeter Gage...........................................3-47
Audio System(s).............................................3-48
Setting the Clock..........................................3-48
Radio(s)......................................................3-49
Theft-Deterrent Feature..................................3-57
Radio Reception...........................................3-58
Fixed Mast Antenna......................................3-58
Chime Level Adjustment................................3-58
Section 3 Instrument Panel
3-2
How to Add Fluid
To add transmission fluid, do the following:
1. Remove the filler plug.
2. Add fluid at the filler plug hole. Add only enough
fluid to bring the fluid level up to the bottom of the
fill opening. Refer to the Maintenance Schedule
to determine the proper fluid to use. SeePart
C: Recommended Fluids and Lubricants on
page 6-31.
3. Reinstall the filler plug. Be sure the plug is fully
seated.
Cooling System
When you decide it is safe to lift the hood, here is what
you will see:
A. Engine Fan
B. Coolant Surge Tank
If your vehicle has a Caterpillar
®diesel engine, see the
Caterpillar®Diesel Engine Operation and Maintenance
Manual provided with your vehicle.
If the coolant inside the coolant surge tank is boiling, do
not do anything else until it cools down. The vehicle
should be parked on a level surface.
5-43
The coolant level should
be at the FULL COLD
mark or higher. If it is not,
you may have a leak at
the pressure cap or in the
radiator hoses, heater
hoses, radiator, water
pump, or somewhere else
in the cooling system.
{CAUTION:
Heater and radiator hoses, and other engine parts,
can be very hot. Do not touch them. If you do, you
can be burned.
Do not run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine fire, and you could be burned.
Get any leak fixed before you drive the vehicle.If there seems to be no leak, start the engine again. The
engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal down.
If it does not, your vehicle needs service. Turn off the
engine.
Notice:Engine damage from running the engine
without coolant is not covered by the warranty.
Notice:Using coolant other than DEX-COOL can
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs first. Any repairs
would not be covered by the vehicle warranty.
Always use DEX-COOL (silicate-free) coolant in
your vehicle.
How to Add Coolant to the Coolant
Surge Tank
If you have not found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible
but the coolant level is not at the FULL COLD mark
or higher, add a 50/50 mixture of clean, drinkable water
and DEX-COOL
®coolant at the coolant surge tank,
but be sure the cooling system, including the coolant
surge tank pressure cap, is cool before you do it.
SeeEngine Coolant (Caterpillar Diesel Engines) on
page 5-47for more information.
5-44
4. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the
engine cooling fan.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge tank
until the level reaches slightly above the FULL
COLD mark.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Engine Coolant (Caterpillar Diesel
Engines)
If your vehicle has a Caterpillar®diesel engine, see the
Caterpillar®Diesel Engine Operation & Maintenance
Manual provided with your vehicle to find out what to add,
as well as when and how to service your cooling system.
Coolant Surge Tank Pressure Cap
The coolant surge tank pressure cap is located in
the engine compartment, on the driver’s side of the
vehicle.
Notice:Your vehicle’s surge tank pressure cap is
designed for use with medium-duty cooling systems
only. If the surge tank pressure cap is not tightly
installed, coolant loss and possible engine damage
may occur. Be sure the cap is properly and tightly
secured.
5-47