The CODE control unit
M20
is through
the 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 coming 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 1 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.