Clock spring

CLOCK SPRING

The clock spring (1) is a device which is fitted on the steering column switch unit and is designed to allow the Air Bag module cables fitted on the steering wheel to follow the rotation of the latter without danger of breaking.

The device consists of two plates, the lower one fixed to the steering column switch unit by means of bolts (2), the upper one attached by means of two elements on the upper section.

Inside the two plates, the connecting cables for the module and the horn buttons are wound around to allow the movements of the steering wheel to be followed.

The clock spring is fitted with a device which automatically stops it from rotating when the steering wheel is removed. This operation is designed to prevent the upper plate, no longer attached to the steering wheel, from rotating freely causing the cables to be unwound or wound, with the possibility of them breaking. When fitting the steering wheel the device is automatically locked.

NOTE: When removing-refitting the clock spring, make sure that it is refitted on the steering column switch unit in the same position in which it was removed.

If, for any reason, the upper clock spring plate should rotate in relation to the lower one so that its position during removal is not known, the CLOCK SPRING MUST BE REPLACED.

When replacing, if the clock spring is supplied as spares separately from the steering column switch unit, it should be fitted with the wheels straight because this is the corresponding position for the new device. The new device is fitted with a safety tab which keeps it locked. This tab should be removed when fitting the steering wheel to allow the system to rotate correctly.

SIDE BAGS

Impact sensors

There is an accelerometric sensor on the two front doors which, in the case of a side impact, transmits a signal to the control unit. This side is also processed inside the control unit which, as a result, decides to operate the Side Bag on the side the impact has occurred on.

In effect, the control unit is equipped with a second safety sensor, which detects side impacts, in exactly the same way as the sensor which detects frontal impacts, and gives the go ahead for the activation of the Side Bag on the side where the impact has occurred. This sensor is positioned so that it only detects impacts on the side on which it is located: e.g. the sensor in the driver's pillar only detects impacts which occur on the left and does not detect impacts on the right side.

NOTE: The sensor should be fitted with the arrow pointing in the direction of travel.

Side Bag module

The Side Bag is housed in the outer part of the front seats towards the window. It consists of a container, incorporated in the seat backrest, which houses the gas generator and the folded bag. The container is fixed to the backrest frame by means of a special bracket.

The gas generator can be electrically activated by means of a signal coming from the electronic control unit. In this way a propellant charge is triggered which releases a compressed gas (argon) which expands in the bag, which is smaller than the front bags. The bag deflates immediately after inflation thanks to an opening in the rear. The seat cover stitching has predetermined rupture lines which allow the bag to come out completely.

Disabling passenger Side Bag (device fitted up to June '99)

When the "no passenger" condition is detected, constantly for at least thirty seconds, the control unit excludes the activation of the passenger Air Bag and the Side Bag. If the sensor then detects the "passnger present" condition, the control unit immediately reactivates the passenger Air Bag and the Side Bag.