Lotus Elise / Lotus Exige. Manual - part 108

Lotus Service Notes Section WD

Page 14

WARNING: The harness connector for the passenger's airbag is accessible only after removing the
fascia top panel, so care should be taken to avoid working in close proximity to the airbag door in case
of unintended deployment.

To replace passenger's airbag

WARNING: The following procedures must be followed in the order listed to temporarily disable the
airbag system whilst working in the immediate vicinity of an airbag. Failure to follow this procedure
could cause unintended airbag deployment, resulting in personal injury and unnecessary airbag system
repairs.
a).

Turn off ignition.

b).

Disconnect the negative battery cable, and tape back to ensure that it cannot contact the battery terminal.

c).

From alongside the steering column, in the area of the column upper fixing, locate and disconnect the

yellow driver's airbag harness connector plug.

For access to the passenger's airbag module, the fascia top panel must first be removed. Refer to sub-
section WD.8.

From the right hand end of the airbag module, pull out the security tag and unplug the harness connector.

Release the two nuts and remove the airbag door tether strap bracket from the module mounting bracket.

Release the four nuts and the dash steady brackets securing the airbag module, and withdraw the module
from its mounting bracket.

WARNING: When carrying a live airbag module, make sure the bag and trim cover are pointed away
from you. In case of an accidental deployment, the bag will then deploy with minimal chance of injury.
When placing a live airbag module on a bench or other surface, always face the bag and trim cover
upwards, away from the surface. This is necessary so that a free space is provided to allow the airbag
to expand in the unlikely event of accidental deployment.

If an airbag deployment has occurred, the chassis scuttle beam, airbag mounting bracket, dash extru-
sions and all associated parts must be carefully examined for distortion and renewed where necessary.

WARNING: Proper operation of the SRS system requires that the vehicle structure remains in its
original production configuration. Any damage to the SRS components and/or their respective mounting
brackets, including the chassis, requires replacement, not repair.

If necessary, fit the airbag mounting brackets to the scuttle beam, and tighten the four M8 fixing bolts to
15 Nm.

Fit the airbag module to the mounting brackets, together with the dash steady brackets. Tighten the four
M6 nuts to 6 Nm.

Fit the airbox door tether strap bracket to the airbag module mounting bracket, and tighten the two nuts to
10 Nm.

Plug in the harness connector into the RH side of the module and retain with the security tag.

10.

Refit the fascia top panel (see sub-section WD.8).

11.

Refit the column shrouds, and when all service work is complete, mate the horn/airbag connector to the
vehicle harness (clipping the connector to the column) and reconnect the battery. Check that the airbag
tell tale lights for a few seconds with ignition, and then goes out.

Lotus Service Notes Section WD

Page 15

WD.12 - SEAT BELT PRE-TENSIONERS

WARNING:
•

Failure to comply with the instructions, safety standards and operating procedures as described
in this section, may cause vehicle damage and/or personal injury.

•

Both driver and passenger seat belt assemblies must be replaced after SRS deployment. Do not
attempt to repair or reuse.

Device Operation

The seat belt pre-tensioners are triggered together with the airbags, and use a pyrotechnic device on each

seat belt reel assembly, to operate a rack and pinion mechanism which applies a tightening force to the belt
reel to remove any slack from the belt. Under normal operation, the rack is fully raised and disengaged from
the pinion, allowing normal spooling of the reel for belt withdrawal and retraction.

When airbag/pre-tensioner triggering conditions apply, the SDM signals ignition of the gas generator, the

pressure from which forces the piston and toothed rack downwards, causing rotation of the pinion gear and a
re-winding of the seat belt webbing. The force sustained by the belt and its user is then controlled by a torsion
bar within the belt reel to limit the deceleration force to which the occupant is subjected during the crash event.

The belt pre-tensioning mechanism is designed to operate only once, such that both belt assemblies

should be renewed after airbag/seat belt pre-tensioner deployment. Activation of the pyrotechnic mechanism
is indicated by the belt reel being locked, and allowing neither extraction nor retraction of the belt.

WARNING: Following an impact in which the pre-tensioning element is activated, the seat belt assem-
bly is rendered inoperable. The car should not be driven until the belt assembly has been renewed.

Electrical connector

Gas generator

Belt reel

Piston

w62

Pinion

Rack

Lotus Service Notes Section WD

Page 16

Removal of Seat Belt Assembly

WARNING: Before removing or refitting a pyrotechnic seat belt assembly, the ignition key should be
withdrawn, and the battery leads disconnected from both positive and negative terminals, and iso-
lated to ensure that accidental contact cannot occur.

Each seat belt reel assembly is secured, via a spacer block, to the seat belt mounting bracket/roof hoop

by a single bolt. Note that an orientation tang is incorporated on the belt reel which engages with a hole in the
spacer, and that the spacer is keyed to the mounting bracket by a roll pin.

Check that the key is removed from the ignition switch.

Disconnect both battery cables, and insulate to ensure that accidental contact cannot occur.

Remove both seats by releasing the seat belt from the seat (noting the 10mm spacer), and the seat
runners or frame from the floor.

Remove the centre tunnel rear cup holder liner after removing the single screw from inside the base.
Remove the two screws then exposed securing the cup holder, and remove the holder, disconnecting the
auxiliary power socket.

Remove the 4 fixings along the top of the cabin rear bulkhead trim panel, and withdraw the panel,
disconnecting the speakers and interior lamp.

Hinge up the plastic cover and release the belt slide from the roof hoop, noting the 5mm spacer.

Allow at least one minute from disconnecting the battery before disconnecting the electrical connector
from the gas generator on the seat belt assembly. Release the Torx head fixing bolt and withdraw the belt
reel assembly and spacer block.

Fitment of Seat Belt Assembly

Each seat belt reel assembly is secured, via a spacer block, to the seat belt mounting bracket/roof hoop

by a single bolt. Note that an orientation tang is incorporated on the belt reel which engages with a hole in the
spacer, and that the spacer is keyed to the mounting bracket by a roll pin.

Fit the seat belt reel assembly and alloy spacer to the bracket on the mounting frame, with the spacer

block located by its roll pin into the hole in the bracket, and the belt reel tang located in the upper hole in
the spacer. Fit and tighten the single Torx head fixing bolt (discarding the cardboard retaining washer if
fitted) to 45 Nm (33 lbf.ft). Plug the harness connector plug into the gas generator on the belt assembly.

Fit the belt slide to the roof hoop with the 5mm spacer interposed, and tighten the special shouldered bolt

to 45 Nm (33 lbf.ft). Check that the hoop is free to pivot. Clip the plastic cover into position.

Refit the cabin rear bulkhead trim panel, connecting the interior lamp and speakers, and retain with the

four screws.

Refit the cup holder, connecting the power socket, and liner.

Refit the seats and fit the seat belt to the seat frame with the 10mm spacer between belt and seat. Tighten

the special shouldered bolt to 33 Nm (24 lbf.ft). Check that the belt eye is free to pivot.

Reconnect the battery, turn on the ignition, and check that the airbag tell tale lamp lights for a few seconds

and then goes out.

Lotus Service Notes Section WD

Page 17

Safety Standard

The pre-tensioning function is energised via pyrotechnic materials, therefore manipulation, handling and

storage MUST be performed to the specified procedures as described to avoid any occurrence of injury to the
operator or damage to the pre-tensioning unit.

In normal conditions, the pre-tensioner assembly can only be activated through the action of the electric

ignition control during impact. During the activation phase of the pyrotechnic charge, small gas quantities are
developed. The main constituent of the gases is Nitrogen:
Note! This gas is not toxic.

The pre-tensioner assemblies must be protected against exposure;

To temperatures over 90°C (195°F) at contact with surfaces

90°C during 106 hrs.

From sparks and naked flames.

WARNING: If exposed to temperatures in excess of 140°C, self-ignition of the pyrotechnic charge of
the gas generator may occur. Exposure to temperatures in excess of 165°C, self-ignition of the
pyrotechnic charge will occur.

Also, if exposed to temperatures between 90°C (285°F) and 165°C (330°F), deterioration of the pyrotechnic

charge ignition is possible. The consequences of this could be failure to activate at prescribed levels. The pre-
tensioner must be protected against stresses, shocks and dropping. Pre-tensioners that have been subjected
to such treatment must be discarded and returned to the supplier with accompanying paperwork describing the
reasons for return.

Never store pre-tensioner assemblies with other flammable or combustible materials. Gas generators

MUST be prevented from coming into contact with acid, water, grease and heavy metals: Contact with these
substances may cause toxic or dangerous gases, or explosive mixtures.

Any residual fuel of the gas generator, not burned during ignition, is slightly flammable. The unit, there-

fore, must never be disassembled, damaged or the parts manipulated. Any advertising or demonstrations of
the pre-tensioner assembly should only be carried out using inert pre-tensioners (without the pyrotechnic charge).
The base of the pre-tensioner must be painted green, with visible and indelible wording, stating ‘Inert Assem-
bly’. It must incorporate the KSS logo, signed with indelible ink by the person responsible for the supply of the
product.

WARNING: Never disassemble the pre-tensioner or any of it’s components!

Transportation of belt with pre-tensioner

Transport on road vehicles should be carried out with the assemblies stored in the luggage compartment.

Never transport in the passenger compartment. Never transport the pre-tensioner manually or holding it by the
webbing: this can result in damage to the assembly.

Storage of belt with pre-tensioner

Belts with pre-tensioning elements should be stored in containers or boxes that can be locked with a key,

and ventilated. They MUST be stored in an area free from flames and heat sources. On completion of work, or
during work break periods, pre-tensioner belts should be returned to the storage container and locked with a
key.

Disposal of belts with pre-tensioner

Charged pre-tensioners to be scrapped and not fitted to a car must be activated. This should be carried

out only by the belt manufacturers, or specialised workshops.

Vehicle disposal

Charged pre-tensioners fitted to a vehicle MUST be removed before the vehicle is dismantled for scrap-

ping. If the pre-tensioner is not activated during an accident, the device must be considered as still to be in a
'charged' condition.

General safety instructions/dangers for health
-

When handling activated pre-tensioners, use safety glasses and vinylic or nitrylic protection gloves.

After handling a loaded pre-tensioner, wash hands with soap and water.

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