high idle speed is being controlled by the engine
software, not the driver.
A steadily illuminated high temperature (HEST) lamp
alerts the operator of high exhaust temperature dur-
ing the regeneration process, if vehicle speed is
below 5 mph (8 km/h). The HEST lamp does not sig-
nify the need for any kind of vehicle or engine ser-
vice; it only alerts the vehicle operator of high ex-
haust temperatures. Make sure the engine exhaust
pipe outlet is not directed at any person, or at any
surface or material that will melt, burn, or explode.
See
Fig. 7.1
.
WARNING
Active regeneration can occur automatically any-
time the vehicle is moving. The exhaust gas tem-
perature could reach 1500°F (816°C), which is hot
enough to cause a fire, heat damage to objects
or materials, or personal injury to persons near
the exhaust outlet. See
Regen-Inhibit Switch
later
in this chapter for instructions on preventing au-
tomatic regen if necessary.
The exhaust temperature can remain high even
after the vehicle has stopped. When stopping the
vehicle shortly after an automatic regen, ensure
the exhaust outlets are directed away from struc-
tures, trees, vegetation, flammable materials, and
anything else that may be damaged or injured by
exposure to high heat.
A steadily illuminated yellow diesel particulate filter
(DPF) lamp indicates that a regen may be required
soon. Bring the vehicle to highway speeds to allow
for an active regen, or a parked regen should be
scheduled for the earliest convenient time. See
Fig. 7.2
.
A DPF lamp blinking at the same time as a steadily
illuminated yellow Check Engine lamp, indicates that
a parked regen must be performed immediately, or
an engine derate will occur. If the red Stop Engine
lamp illuminates with the blinking DPF lamp and the
Check Engine lamp, a parked regen must occur or
an engine shutdown will occur. Park the vehicle and
perform a parked regen. See
Fig. 7.3
.
A steadily illuminated yellow malfunction indicator
lamp (MIL) indicates an engine fault that affects the
emissions. See
Fig. 7.4
.
When diesel particulate filter servicing is needed, it
must be performed by an authorized technician, and
a record must be maintained for warranty purposes.
The record must include:
•
date of cleaning or replacement;
•
vehicle mileage;
•
particulate filter part number and serial number.
09/25/2006
f610816a
Fig. 7.1, High Exhaust System Temperature (HEST)
Lamp
09/25/2006
f610815a
Fig. 7.2, Diesel Particulate Filter (DPF) Status Lamp
03/20/2008
f611000
1
2
3
CHECK
STOP
1.
Stop Engine Override Switch
2.
Amber Check Engine Warning Lamp
3.
Red Stop Engine Lamp
Fig. 7.3, Engine Lamps
Engines and Clutches
7.2
