The CODE control unit
M20 is supplied
with power at pin 3 from the battery from the line of maxifuse EFI
B99, through a line protected by fuse F5 of the additional fuse
box B98 A.
The supply controlled by the ignition (15/54)
arrives at pin 8 from the line protected by fuse
F4
of the
additional fuse box
B98 A
.
Pin 4 is earthed.
The line leading from pin 6 is a serial
line leading to engine management unit
M10
, which is responsible
for identifying the key and exchanging codes.
The control unit is equipped with a self-diagnostic
unit that may be used by connecting the unit to connector
R10
:
this receives signals from pin 5 of control unit
M20
through
the tester line.
The self-test system also produces the signal
for the 'CODE failure' warning light, located in the check instrument
E30
, which comes out of pin 2 of the control unit
M20
.
The check module
E30 receives a supply
controlled by the ignition (INT) at pin 13 from the line protected
by fuse F4 of supplementary fuse box B98B; when this earth signal
arrives, the 'CODE failure' warning light comes on.A second control unit connector is connected
via two leads to the aerial, fitted coaxially to the ignition key,
in order to detect key insertion and rotation.