Exhaust Restrictor (Engine Warm-Up) - Chevrolet Kodiak 2008 Owner's Manual

Exhaust Restrictor (Engine
Warm-Up)
Exhaust Restrictor
If your 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 your vehicle has a DURAMAX
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.
2-22
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6600 engine, it has a
For all engines this feature is already turned on. The
automatic quick warm-up on the DURAMAX
can be turned off and on by doing the following
procedure:
1. Turn the ignition to 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.
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engine