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BCU 370 · Edition 01.19
38
Function
3 .6 .1 Reaction to process faults
The BCU 370 reacts differently to process faults in different program steps. If, for example, the signal from air
pressure switch DL drops during pre-purge,
1
flashes on the display and a timeout time of 25 seconds starts to
elapse. If the signal is not applied again, the BCU carries out three further start-up attempts.
Process fault
BCU 370’s reaction
Signal
(terminal)
Signal status
During program step
Con
tr
ol
le
d s
hu
t-
do
wn
Ti
m
eo
ut 2
5 s
Im
m
ed
ia
te
fault
lo
ck
-o
ut
Saf
et
y s
hu
t-
dow
n
St
ar
t-
up
at
tem
pt
s
1)
Rest
ar
t
2)
Fa
ult
m
es
sag
e
DG
max.
(11)
drops
XX
All
X
DG
min.
(9)
drops
XX
All except t
SA1
+ t
SA2
4)
X
not pending after t
SA1
04
t
SA1
4)
4
not pending after t
SA2
06
t
SA2
4)
6
DL (7)
pending
0
"no flow" state check
0
not pending
1
Operating position check
1
drops
P1
Pre-purge time
P
drops
A2
Valve moves to Ignition position
2
drops
02
Waiting time
2
drops
03
Pre-ignition time
3
drops
04
t
SA1
4
drops
05
t
FS1
5
drops
06
t
SA2
6
drops
07
t
FS2
7
drops
H8
Controller enable waiting time
8
▼