“Stop Engine Override” switch, located
on the instrument panel, until a safe
stop can be made. The operator only
needs to press the override switch
every 15 to 20 seconds to prevent
engine shutdown from occurring.
An important thing to remember is
that it takes 30 seconds from the time
the automatic shutdown sequence
begins until engine shutdown. There-
fore, the operator
must
press the over-
ride switch just prior to engine shutdown
and continue to do so until the vehicle
can be brought to a safe stop.
The immediate speed reduction
option
will bring engine rpm back to a
predetermined speed, but will not shut
down the engine.
The engine should not be restarted
after it has been shut down by the
engine protection system unless the
problem has been located and cor-
rected.
The conditions that will cause the
“Stop Engine” light (SEL) to come on
are:
• Loss of coolant
• High oil temperature
• Low oil pressure
• Auxiliary shutdown
It is important to point out that when-
ever the “Check Engine” light (CEL) or
the “Stop Engine” light (SEL) comes
on, the DDEC computer will determine
where the problem is, and will then
store this information in its memory.
If the malfunction is intermittent, the
“Lights” will come on and go off as the
computer senses the changing engine
condition.
A special diagnostic tool (Diagnostic
Data Reader, or “DDR”) is available that
can be plugged into the engine com-
puter memory to extract information
related to the cause of the problem.
Once the malfunction has been cor-
rected, the DDEC system will return
the engine to normal operation.
The DDR can distinguish between
codes now active and those stored in
the ECM memory (inactive).
The diagnostic code recorded in the
computer memory will remain until it is
erased by a technician.
15
On engines equipped with Jacobs
Engine Brakes,
the “Jake Brake” cir-
cuit can be activated by releasing
the EFPA (Electronic Foot Pedal
Assembly) completely to the idle
position. The “Jake Brake” will then
operate the same as on engines with
mechanical governors. To return the
vehicle to cruise speed after brake or
clutch application, simply activate
the “Resume” switch. Each subse-
quent touch of the “Resume” switch
will increase cruise speed by 1 mile
(1.6 km) per hour.
DDEC Operation
Since the DDEC system is electronic, a
battery is required to operate the com-
puter.
The system operates at 12 volts.
However, in the event of a power sup-
ply malfunction, the system will contin-
ue to operate at reduced voltage.
At reduced voltage, the electronic
control system will detect a malfunction.
When this occurs the “Check Engine”
light (CEL) will come on.
At this point, the Electronic Control
Module will go into “Back Up Control.”
You should then notice a change in
engine operation, and at this time cer-
tain DDEC options, such as cruise con-
trol, smoke control, and automatic
shutdown, will not function.
The engine will operate only at
reduced rpm. You will be able to oper-
ate the vehicle at reduced voltage until
the battery voltage has reached a point
where it will no longer function and the
engine will shut down.
You can still operate the vehicle and
proceed to your designation when the
“Check Engine” light (CEL) comes on.
However, a report should be made to a
DDEC technician as soon as possible.
The “Stop Engine” malfunction is
recorded in the Electronic Control
Module. With the 30 second shutdown
option, the engine will begin a 30 sec-
ond, stepped, power down sequence
until it shuts down completely.
To allow for the possibility of the
“Stop Engine” automatic shutdown
function being activated while the
vehicle is operating in a critical situa-
tion, an override is provided.
NOTE:
In some applications the “Stop
Engine Override” and “Diagnostic
Request” switches can be the same.
In this situation the operator may
elect to override the automatic stop
engine sequence by pressing the
14
CAUTION:
To avoid the possibility of vehicle
damage and/or personal injury,
Detroit Diesel does not recom-
mend using cruise control under
the following conditions:
• When it is not possible to keep
the vehicle at a constant speed
(on winding roads, in heavy traf-
fic, in traffic that varies in speed,
etc.).
• On slippery roads (wet pave-
ment, ice or snow-covered roads,
loose gravel, etc.).
NOTICE:
When the “Stop Engine” light
comes on, the computer has
detected a major malfunction in the
engine that requires immediate
attention. It is the operator's
responsibility to shut down the
engine to avoid serious damage.
NOTICE:
For some applications, holding the
“Stop Engine Override” switch in will
not prevent the engine shutdown
sequence. You must continue to
reset the automatic shutdown sys-
tem by pressing the “Stop Engine
Override” switch at intervals of
approximately 15 to 20 seconds.
STOP ENGINE
DIAGNOSTIC
CHECK
STOP
SWITCH
OVERRIDE
ENGINE
ENGINE
ON
OFF
Typical Shutdown Override Switch and
Engine Lights
Summary of Contents for 92 Series
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