airbag RENAULT KANGOO 1997 KC / 1.G Electrical Equipment User Guide

DI8816 DI8817
WIRING
Airbags and seat belt pretensioners
88
FUNCTION AND OPERATION OF THE AIRBAGS AND PRETENSIONERS
1) Function
In the event of an accident, the airbag prevents the head striking the steering wheel or dashboard.
It also reduces the maximum acceleration of the head, by absorption.
2) Trigger threshold
Generally speaking, there are four different basic situations.
1) FRONTAL IMPACT AGAINST A OBSTACLE
The trigger speed depends on the obstacle’s
surface. The softer the surface, the higher the
speed.
The pretensioner generally triggers at a lower
speed than the airbag.
2) OFFSET IMPACT AGAINST A OBSTACLE
In this case, the airbag trigger speed depends on
the angle of impact α.
The greater the angle, the higher the vehicle
speed for triggering.
ADirection of travel
BCentre of gravity
88-9

DI8819 DI8818
WIRING
Airbags and seat belt pretensioners
88
3) FRONTAL IMPACT AGAINST A FLEXIBLE
OBSTACLE
The airbag trigger speed depends in this case on
the degree of flexibility of the bodywork of the
vehicle hit.
The more flexible the other vehicle, the higher the
trigger speed (for vehicles of equal flexibility and
100 % contact, the speed is higher than 40 km/h)
(relative speed).
4) OFFSET IMPACT AGAINST A FLEXIBLE
OBSTACLE
Here the airbag trigger speed depends on the an-
gle of impact α and the flexibility of the vehicle hit
in the direction of travel.
The vehicle speed for airbag triggering is greater
when the angle of impact α is greater and the
flexibility of the vehicle hit is high.
5) SUMMARY AND CONCLUSION
- The airbag only reacts to deceleration in the direction of driving. A side impact or the vehicle rolling over
cannot trigger the airbag.
- The vehicle’s projectile energy is transformed into deformation energy of the front part of the vehicle.
Deceleration is greater when the deformation of the vehicle hit is less, meaning that the airbag will trigger
much earlier.
- The minimum speed at which the airbag is triggered is greater when the angle of impact α is large (see
above).
- If, in a frontal impact, there is no deformation at the front pillars, or engine - gearbox - sub-frame impact,
the fact that the airbag was not triggered cannot be considered as a fault since the trigger speed may not
have been reached.
- The pretensioners always trigger at a lower speed than the airbag.
- Experience has shown that the impact speeds given by customers are often not correct. Their reactions are
generally reduced by shock: there is almost always confusion between the cruising speed before the im-
pact and the actual speed of the impact which is thankfully much lower in most cases.
ADirection of travel
BCentre of gravity
CImmobilised vehicle
88-10

WIRING
Airbags and seat belt pretensioners
88
92656S
The new 30-track computers are provided with
the K and L lines for fault finding with the XR25
(except for vehicles with pretensioners only).
This enables computer faults or faulty lines to be
detected in the system (see section on fault fin-
ding).
NOTE: before each operation an auxiliary func-
tion enables the ignition lines to be de-activated
to prevent the risk of triggering the pyrotechnic
gas generators.
Various vehicle configurations are possible:
Vehicle fitted with:
- pretensioners only,
- pretensioners and driver’s airbag,
- pretensioners and driver’s airbag and passen-
ger’s airbag.
NOTE :
• A vehicle fitted with a driver’s airbag will be
identified by a label in the bottom corner of
the windscreen on the driver’s side, and by the
word "Airbag" in the centre of the steering
wheel.
• If a passenger airbag is fitted, a second label is
located in the lower corner of the windscreen
on the passenger side and the word "Airbag" is
located on the dashboard on the same side.
Each time the windscreen is replaced, remember
to fit the labels showing that the vehicle is fitted
with airbags.
These labels are available in a kit Part Number :
77 01 205 442.
SPECIAL TOOLING
PRESENTATION
XR25
88-11

WIRING
Airbags and seat belt pretensioners
88
PRD99498
This bornier is connected instead of the computer,
fitted with a single 30-track connector.
It enables all the ignition lines to be checked by
means of the XRBAG, the supply voltage of the
computer to be measured, and the airbag war-
ning light on the instrument panel to be illumina-
ted.
Terminals also enable the continuity checks to be
carried out on the diagnostic lines, the warning
light lines and the feed to the computer (see sec-
tion on fault finding).
XRBAG TEST UNIT (Elé. 1288)
96833G
This unit is a tool specifically designed for testing
and fault finding on airbag devices and seat belt
pretensioners.
It enables electrical measurements to be carried
out on the different lines in the systems.
(See "fault finding" section).
IMPORTANT: It is not permitted to carry out mea-
surements on these systems with an ohmmeter or
any other electrical measuring instrument: there
is a risk of triggering due to the operating current
of the instrument.
XRBAG 30-TRACK ADAPTER
88-12

WIRING
Airbags and seat belt pretensioners
88
DUMMY AIRBAG IGNITION MODULE
A dummy airbag ignition module housed in a
small red box is supplied in the case containing
the XRBAG test kit.
It has the same electrical characteristics as a real
ignition module and its purpose is to replace the
airbag cushion when it is being checked for faults.
Contact your After Sales Head Office for further
information.
DESTRUCTION UNIT
To avoid all possible risks of an accident the
pyrotechnic gas generators in the airbags and seat
belt pretensioners must be triggered before the
vehicle or the individual part is scrapped.
It is
ESSENTIAL to use the tool Ele. 1287 for this
purpose.
96832R
Refer to the section entitled "Destruction
procedure".
IMPORTANT: Do not trigger pretensioners which
must be returned under warranty for a stalk pro-
blem. This makes analysis by the supplier impossi-
ble.
Return the part in the packaging of the new part.
88-13

WIRING
Airbags and seat belt pretensioners
88
When refitting the computer, it MUST be moun-
ted on the vehicle before its connectors are re-
connected.
The arrow on the computer must point towards
the front of the vehicle.
Vehicle fitted with airbag(s)
Lock the computer using the XR25 and command
G80* (ISO selector on S8 code D49).
When this function is active, all the trigger lines
are inhibited, the airbag warning light on the ins-
trument panel and bargraph 14 LH on the XR25 il-
luminate (new computers are supplied in this
condition).
When refitting the computer:
- Mount it on the vehicle (the arrow on the
computer must point towards the front of the
vehicle).
- Connect the 30 track computer connector and
carry out a check using the XR25.
If everything is correct, unlock the computer using
command G81*.COMPUTER
Several types of unit may be found:
- one computer for pretensioners only.
- one computer for pretensioners and airbag(s).
Depending on function, these computers have:
- an electromagnetic safety sensor,
- a decelerometer for the airbags
- an ignition circuit for the different pyrote-
chnic systems,
- a power reserve,
- a diagnostic and detected fault storage circuit
(except pretensioner only),
- a control circuit for the warning light on the
instrument panel (except pretensioner only),
- a K - L communication interface via the dia-
gnostic socket (except pretensioner only).
IMPORTANT
Before removing the computer:
Vehicle with pretensioners only (no air-bag) :
- Switch off the ignition.
- Remove the feed fuse (see fuse allocation) and
wait for 5 minutes for the reserve capacity to
discharge.
- Disconnect the computer connector to avoid
any risk of triggering.
- Ensure no-one is in the passenger compartment
during the complete operation on the compu-
ter.
88-14

WIRING
Airbags and seat belt pretensioners
88
LOCATION OF THE COMPUTER
It is located on the tunnel in the central console.
13059S
COMPUTER WITHOUT AIRBAG
98715S
COMPUTER WITH AIRBAG(S)
98716S
IMPORTANT:
• The computer must be replaced after the pre-
tensioners and airbags have been triggered.
Certain components will lose their nominal cha-
racteristics after the trigger energy has passed
through them.
• When replacing an airbag(s) computer, the
computer must be unlocked using the XR25 be-
fore it is used (see "Fault finding" section " : in-
terpretation of bargraph 14 LH side).
IMPORTANT :When refitting the computer, it
MUST be mounted on the vehicle before its
connectors are reconnected. The arrow on the
computer must point towards the front of the
vehicle (tightening torque : 0.4 daN.m).
NOTE: The 30 track connector for the computer
short circuits the various trigger lines as soon as it
is disconnected. Shunts located opposite each pre-
tensioner line or airbag line prevent the incorrect
triggering of these systems (by aerial effect for
example).
88-15

WIRING
Airbags and seat belt pretensioners
88
IMPORTANT:
• When carrying out an operation under the ve-
hicle (exhaust, bodywork, etc.), do not use a
hammer or transmit impacts to the floor wi-
thout having removed the pretensioner fuse
and waited 5 minutes for the reserve capacity
to discharge (see section "Fuse allocation", in
the "Wiring diagram" technical note) or for ve-
hicles with the airbag function, wait for 2 se-
conds for the unit to discharge automatically.
• When fitting an electrical accessory in After
Sales, (speaker, alarm unit or any equipment
which may create a magnetic field), it must not
be located near the airbag and pretensioner
computer.CONNECTION
2 track connector
(located under the front seats)
Pretensioner triggering.
NOTE: The pretensioner trigger line connectors
short circuit (tab holder side) when they are dis-
connected, which prevents incorrect triggering of
the systems (aerial effect for example).
30 track connecter (fullest version)
Track Allocation
1 + Driver’s pretensioner
2 - Driver’s pretensioner
3 + Passenger’s pretensioner
4 - Passenger’s pretensioner
5 + After ignition
6 + Passenger’s airbag (line 1)
7 - Passenger’s airbag (line 1)
8 Warning light
9 Earth
10 + Driver’s airbag
11 - Driver’s airbag
12 Diagnostic line "K"
13 + Passenger airbag (line 2)
14 - Passenger airbag (line 2)
15 Diagnostic line "L"
16
17Shunt
18
19Shunt
20 Not used
21
22Shunt
23 Not used
24 Not used
25
26Shunt
27 Not used
28
29Shunt
30 Not used
NOTE : The computer and ignition modules are
normally fed from the vehicle battery.
A reserve capacity is however included in the
computer in case the battery is disconnected at
the start of the impact.
88-16

WIRING
Airbags and seat belt pretensioners
88
WARNING LIGHT ON THE DASHBOARD
This warning light controls the pretensioners and
airbags, except for vehicles fitted with pretensio-
ners only.
It should illuminate for a few seconds when the
ignition is switched on, then extinguish (and
remain extinguished). If it does not illuminate
when the ignition is switched on, or illuminates
when the vehicle is being driven, there is a fault in
the system (see fault finding section).
IMPORTANT : the systems MUST be checked by
means of the
XRBAG, following:
- an accident which has not given rise to
triggering,
- theft or attempted theft of the vehicle,
- before the sale of a used vehicle.
These systems are not triggered in the case of:
- a lateral impact,
- a rear impact.
When it is triggered the pyrotechnic gas
generator produces an explosion combined with
light smoke.
NOTE : With pretensioners only,the computer has
a single sensor (electromechanical).
OPERATIONS ON THE TRIGGER LINES
If a fault is noted on one of these lines, the
component must be renewed and not repaired.
This safety equipment cannot be subjected to any
conventional wiring or connector repair opera-
tions.
The airbag trigger wiring is integrated into the
passenger compartment wiring loom . To make
replacement easier, cut the two ends of the faulty
wiring and run the new wiring along the same
routing, alongside the passenger compartment
wiring loom.
IMPORTANT : When fitting the new wiring, en-
sure it is not in danger of being cut or rubbed and
that the original wiring cleanliness is respected.
NOTE : The trigger lines are supplied by the Parts
Department in a kit containing both airbag and
pretensioner wiring.
OPERATION WITH AIRBAG(S) AND PRETENSIONER
EQUIPMENT
When the ignition is switched on, the
warning light illuminates for a few
seconds then extinguishes.
This computer is then on standby and notes dece-
lerations of the vehicle using the signal measured
by the integral decelerometer.
When a frontal impact of sufficient strength oc-
curs it triggers the simultaneous ignition of the
pyrotechnic generators of the two seat belt pre-
tensioners after receiving confirmation of detec-
tion of an impact by the electromechanical safety
sensor.
Under the action of the gases generated by the
system, a piston is displaced in its cylinder,
carrying with it a cable connected to the
corresponding central catch, thus enabling the
seat belt to be retracted (see pretensioner
section).
If the frontal impact is greater than this, the dece-
lerometer triggers the ignition of the pyrotechnic
gas generators which inflate the driver and pas-
senger airbags once the impact has been valida-
ted by the electromechanical safety sensor.
88-17

WIRING
Airbags and seat belt pretensioners
88
DI8801R
A pretensioner includes:
- a special seat belt catch (A),
- a pyrotechnic gas generator and ignition
module (B).
SEAT BELT PRETENSIONERS
DESCRIPTION
They are mounted on the side of the front seats.
96438S
DI8802
The components of the pretensioner cannot be se-
parated. When it is triggered the system is able to retract
the seat belt catch by up to 70 mm (maximum)
88-18