Freelander System Description and Operation
RESTRAINT SYSTEMS
75-6
DESCRIPTION AND OPERATION
Power Back-up
The airbag DCU incorporates capacitors to ensure the system will function if the external power supply is
disconnected during a collision:
l
Up to 2002 MY, the DCU incorporates a hardware capacitor, that provides power for 200 milliseconds to enable
system operation and collision recording, and individual capacitors that provide power for 150 milliseconds for
each fire signal output.
l
From 2002 MY, the DCU incorporates individual capacitors that provide power for 150 milliseconds for each
airbag fire signal output.
The capacitors are kept charged while the ignition is on by a dc-dc voltage converter incorporated into the airbag DCU.
It can take up to 10 minutes from the ignition being switched off for the energy stored in the capacitors to fully dissipate
and make the system inert.
Airbag DCU Connector Pin Details (Up To 2002 MY)
Airbag DCU Connector Pin Details (From 2002 MY)
Pin No.
Description
Input/Output
1
RH pretensioner (+ve)
Output
2
RH pretensioner (-ve)
Output
3
LH pretensioner (+ve)
Output
4
LH pretensioner (-ve)
Output
5
Power supply
Input
6
Vehicle earth
–
7
SRS warning lamp
Output
8
Not used
–
9
ISO 9141 K line
Input/Output
10
Driver airbag module (+ve)
Output
11
Driver's airbag module (-ve)
Output
12
Not used
-
13
Passenger's airbag (+ve)
Output
14
Passenger's airbag (-ve)
Output
15 to 30
Not used
-
Pin No.
Description
Input/Output
1 to 25
Not used
–
26
Ignition power supply
Input
27
SRS warning lamp
Output
28
Vehicle earth
–
29
Driver airbag module (–ve)
Output
30
Driver airbag module (+ve)
Output
31
Passenger's airbag (+ve)
Output
32
Passenger's airbag (–ve)
Output
33
LH pretensioner (–ve)
Output
34
LH pretensioner (+ve)
Output
35
RH pretensioner (–ve)
Output
36
RH pretensioner (+ve)
Output
37 to 53
Not used
–
54
ISO 9141 K line
Input/Output
55 to 75
Not used
–