Ciu - Control Interface Unit; Dcu - Display Control Unit - Volvo TAD650VE Workshop Manual

Group 30: Electrical system EMS 2 - "Engine Management System"

CIU - Control Interface Unit

The CIU is a "translator" between the CAN bus and
the customer's own control panel. This unit has two
serial communication links, one fast and one slow.
The fast one is a CAN link that features a bus speed
of 250 Kbit/s. All data regarding instruments, indicator
lamps, contacts and potentiometers are controlled by
this bus.
The slower J1708/J1587 link handles diagnostic infor-
mation for, among other things, the flashing code. The
VODIA diagnosis tool also uses the J1708/J1587 link
to communicate with the system.

DCU - Display Control Unit

DCU is a digital instrument panel that communicates
with the engine control module via the CAN link. DCU
has several functions, such as:
Engine control
– Start, stop, speed control, preheating etc.
Monitoring
– Engine speed, boost pressure, boost temperature,
coolant temperature, oil pressure, oil temperature,
engine hours, battery voltage, instantaneous fuel
consumption and fuel consumption (trip fuel).
Diagnostics
– Shows fault codes in text. Lists previous faults.
Parameter setting
– Idling speed, alarm limit for oil temperature/cool-
ant temperature, droop.
– Preheating for ignition.
Information
– Information about hardware, software and engine
identification.
9