Deceleration Sensors - Fiat 1998 Marea Service Manual

Marea- Marea Weekend
1999 range
The connection points between the side bag module, air bag system and passenger presence sensor (leads
with yellow sheath) are located on the bottom of the seat at the front inside a protective box.
The side bag module and passenger presence sensor connections are anchored in a box secured beneath
the passenger seat.
When necessary to carry out checks on the system or remove the seat to gain access to the connections
located inside the box, open the cover by undoing the retaining clips and prising up the box safety cap
(see Removing-Refitting front seat with passener presence detector and side bag).
Seat with side bag and passenger presence sensor (PPD)
1. Side bag module
2. Passenger presence sensor (PPD)
3. Box protecting connections
4. Side bag module connection
5. Passenger presence sensor connection (PPD)
6. Electronic interface device
An electronic device located in the lower part of the seat acts as an interface between signals from the
control unit and signals from the passenger presence sensor (PPD).

DECELERATION SENSORS

The deceleration sensors are secured to the central car pillars and contain an accelerometer that can detect
acceleration that takes place during side impact.
If the impact exceeds a set severity level, the information is transferred from the relevant sensor to the main
air bag system control unit, which compares the information with input from a second acclerometer inside
the control unit itself, which guarantees a safety function.
If the acclerometric signals detected by the satellite sensor and the control unit agree with one another,
the main control unit sets off the side bag module on the side affected by impact.
If the impact is on the passenger side, the main control unit compares the signal from the deceleration
sensor with a signal from the passenger presence sensor to determine whether or not to set off the side
bag module.
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Electrical equipment
Air Bag - New features
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