IDENTIFICATION
These data are evaluated together
with the data from the sensors on
the engine, such as coolant and
fuel temperature and oil and charge
pressure.
The data is then compared to the
characteristic maps or lines stored in
the DDEC-ECU. From these data,
quantity and timing of injection are
calculated and the unit pumps are
actuated accordingly through the
solenoid valves.
NOTE:
To obtain a replacement DDEC-ECU,
all the data given on the DDEC-ECU
label are required.
The DDEC-ECU data label has the 10
digit engine serial number (see Figure
14), the engine horse power and
torque.
DDEC-VCU
The DDEC-VCU communicates
with any other electronic control unit
installed on the vehicle over the J1587
data link. See Figure 18.
Data for speci
fi
c applications is stored
in the DDEC-VCU. These include idle
speed, maximum running speed, and
speed limitation.
Figure 18 DDEC-VCU
The DDEC-VCU receives data from
the following sources:
□
The operator (accelerator pedal
position, engine brake switch)
□
Other electronic control units
(for example, the anti-lock brake
system)
□
The DDEC—ECU (oil pressure
and coolant temperature)
From these data, instructions are
computed for controlling the engine
and transmitted to the DDEC-ECU via
the proprietary datalink.
The DDEC-VCU controls
various systems, for example,
communications with the datalink, the
engine brake, and the constant-throttle
valves.
26
All information subject to change without notice.
(Rev. )
DDC-SVC-MAN-0055
Copyright © 2009 DETROIT DIESEL CORPORATION
Summary of Contents for EPA04 MBE 900
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