Lotus Eleven/Elise/Exige. Manual - part 122

Lotus Service Notes Section WD

Page 15

the yellow harness connector.

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 a driver's airbag is deployed, refer to steering section HG to determine whether the steering column
telescoping mechanism has been activated, and if necessary, renew the column assembly.

Mate the new airbag yellow connector plug with the harness plug in the steering wheel hub, and locate the
module into the steering wheel. Fit the two socket head retaining screws and tighten to 7Nm.

When all service work is complete, connect the harness plug alongside the steering column, and recon-
nect the battery. Turn on the ignition and check that the airbag tell tale lights for a few seconds and then
goes out.

WD.10 - ROTARY CONNECTOR

WARNING: The rotary connector MUST be replaced after SRS deployment even if there is no visible
damage.

The rotary connector is a device which fits between the steering wheel and column, and allows the

steering wheel to turn whilst maintaining electrical continuity to the airbag module and horn buttons. The
assembly consists of an annular housing fitted over the top end of the steering column, and containing a coil of
four wires. The wires are:
-

+ve feed to the inflator module (switched by the safing sensor);

ground to the inflator module (switched by the microprocessor accelerometer);

input to the horn buttons;

output from the horn buttons.
The steering column side of the device is fitted with a 4 way connector block which plugs into the SRS

harness. The steering wheel side of the device has two 2-way connector plugs, one for the airbag module, and
one for the horn buttons. The coil housing is constructed in two parts, with the outer part fixed to the outer
(stationary column, and the inner part keyed to the inner (rotating) column.

The two parts of the coil housing slide inside of each other in such a way as to allow the steering wheel

to be rotated through its full travel, lock to lock, whilst maintaining an unbroken feed to each of the four circuits
in the steering wheel hub, via the continuous wires in the coils.

In order to help prevent unwanted deployment of the air bag when servicing the steering column or other

SIR components, a shorting bar is incorporated in the rotary connector side of the 4-way SRS harness con-
nector plug. This shorting bar operates when the connector is unplugged, to short across the feed and return
connections to the inflator module. Thus, if a positive feed, or earth is inadvertently applied to the connector
terminals, both sides of the inflator module will be subject to the same potential, and no deployment will occur.

When servicing the rotary connector, it is most important that the correct orientation of the connector is

maintained on refitment, or the connector will run out of travel and be broken.

To replace the rotary connector
1.

Remove the airbag module from the steering wheel (see sub-section WD.8).

Disconnect the horn harness plug.

Bend back the locking tabs and release the nut securing the wheel to the column. Before attempting to
remove the wheel, ensure the front wheels are pointing straight ahead, and match mark the position of
the steering wheel hub against the column to aid re-assembly.

Using a suitable steering wheel puller tool, position the legs to reach through the holes in the wheel hub

Lotus Service Notes Section WD

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and bear directly against the hub, without interfering with the rotary connector. The centre screw should
bear against the end of the column. Withdraw the wheel/hub/rotary connector assembly from the column
splines.
Alternatively, for better puller access, the steering wheel can first be removed from the hub by releasing
the four retaining screws.
CAUTION: If excessive force is applied to either the wheel or column without an appropriate
puller, the telescoping mechanism of the outer column may be overridden, necessitating column
replacement.

Release the two countersunk screws retaining the rotary connector to the steering wheel hub.

On refitment, feed the airbag and horn connector plugs on the rotary connector through the hole in the
steering wheel hub, and secure the unit to the hub with the two countersunk screws. If necessary, refit the
steering wheel to the hub and secure with the four screws. Mate the horn buttons harness connector plug.

Before fitting the wheel/hub/rotary connector assembly to the column, the rotary connector must be
centralised: Turn the connector centre element fully counterclockwise until tight, then turn clockwise
approximately 2.5 turns until the arrow marks on the two parts of the rotary connector are aligned. Make
sure the front wheels are pointing straight ahead, and fit the assembly onto the column with the hub to
column match marks (made on disassembly) aligned, and engage the spring loaded pin on the column
switch housing with the slot in the rotary connector.

Fit a new locking tab washer, followed by the steering wheel nut, and torque tighten to 25 Nm (18.5 lbf.ft).
Bend up the locking tabs to secure.

Mate the airbag harness connector plug and fit the airbag module into the steering wheel. Retain with the
two socket head screws and tighten to 7Nm.

10.

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.

WD.11 - PASSENGER AIRBAG MODULE

WARNING: Safety precautions must be observed when handling a deployed airbag. After deploy-
ment, the airbag surface may contain a white packing powder used to ease deployment, together with
a small amount of sodium hydroxide dust, a by-product of the sodium azide reaction during deploy-
ment that can be irritating to the skin if left on for an extended period of time. Always wear gloves and
safety glasses when handling a deployed inflator module, and wash your hands with a mild soap and
water afterwards.

The passenger's airbag (or inflator module) is housed within the passenger side of the fascia, mounted on

a bracket to the scuttle beam, and arranged to deploy via an aperture in the dash panel covered by a trimmed
'door'. The door is designed to break away in the event of airbag deployment, but is tethered to the dash by two
restraining straps. The airbag module comprises:
-

an inflatable fabric bag;

an inflator (canister of gas generating material)

an initiator (or 'squib')
When the vehicle suffers a forward deceleration of sufficient magnitude to close both the safing sensor

and integrated accelerometer within the SDM, current flows through the deployment loop of both the driver and
passenger airbag module initiators and ignites the gas generating material. Each bag inflates in a fraction of a
second, the passenger's bag bursting through the dash panel 'door', and then deflates via vents in the bag, with
the whole cycle taking less than one second. The airbag is designed for a single deployment, and must then be
renewed.

Lotus Service Notes Section WD

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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.

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.

Lotus Service Notes Section WD

Page 18

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

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