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Control unit
Control unit 9058 houses the electronics for regulating
fuel flow. The electronic system has two microproces-
sors, a main processor M1, that normally looks after all
engine and vehicle control, and another microprocessor
that takes care of fault diagnostics, communication
with the other control units, that is, ABS/ASR and EST
18. M2 also monitors processor M1and takes over its
functions should M1 break down.
In its original form, the control unit is generally pro-
grammed (part (1) in one of the EE programs) and can-
not be used until it has been programmed with engine
data for some engine variants. For each engine variant
there is a so-called “engine data statement” stored in a
disk. With the help of a PC, the data statement can be
stored in part 2 in the EE program.
Moreover, each control unit is programmed with the
bus data (3), that is, the drive line reduction ratios for
the bus in which the control unit in question is in-
stalled. So-called “customer data” (4), that is, the cruise
control limits and possibly speed limitation are also
programmable.
Voltage feed (+30) from
relay box 3060
Speed signal (24 V
pulse from relay
box 3060)
