E7030 Airbag

Description

The car may be fitted with an electronically-controlled safety system that sets off the front seat belt pretensioners and the driver's Air Bag, passenger Air Bag and Side Bags in the case of frontal and/or side impact of a certain severity.

In the case of a side impact of a certain magnitude, the Side Bag and the corresponding Head Bag are activated (only on the side where the impact took place).

An electronic control unit manages the entire system by controlling all the components and activating the restraint systems (pretensioners and airbags) as necessary.

The control unit is located under the centre console and is rigidly fixed to the bodyshell: in this way the deceleration sensors located inside it are close to the centre of gravity and detect deceleration for the entire vehicle accurately.

There is an accelerometric sensor on the two front door pillars which, in the case of a side impact, transmits a signal to the control unit. This signal is also processed inside the control unit which, as a result, decides on the operation of the Side Bag and the Head Bag on the side where the impact has taken place.

The driver's Air Bag module is located in the centre of the steering wheel; it is fitted on a tilting plate which enables the horn to be operated. The plate houses a metal container which holds the folded airbag and a gas generator that inflates the bag.

A clock spring device allows the airbag module connection leads to turn with the steering wheel without the risk of breakage.

The passenger airbag is located on the facia, above the glove compartment., and is fastened directly to the car crossmember via a special bracket.

The passenger Air Bag can be manually deactivated via a special switch - which can be operated by a key - located at the end of the dashboard, passenger side and is only accessible with the door open. With the key in the OFF position, the control unit also controls the operation of the special 'passenger Air Bag disabled' warning light.

The Side Bag is housed in the outer part of the front seat. The sensor is located in the centre pillar.

The Head Bag consists of a curtain bag which inflates and places itself between the head of the occupants and the side windows. The Head Bag folded bag is located under the roof panel, whilst the rear pillar houses the gas generator. The Head Bag represents further protection for the occupants of the front seats because, in addition to the chest area which is already protected by the Side Bags, it also protects the head.

It also offers the first protection for the occupants of the rear seats.

The pretensioner is a device built into the front seat belt reel.

For more details Characteristic of working principle 5580C Air bag system .

The control unit comes with a self-diagnostic function.

• it detects and memorizes any faults
• it recognizes the various components and the type of fault
• it signals the onset of these faults via the special warning light

System activations following a particularly serious impact are memorized by the control unit.

The system control unit supply line is protected by a fuse located in the junction unit.

When operations are carried out to the Air Bag system the recommended safety instructions must be followed precisely.

For more details [PR5580C].

Description of operation

The Air Bag system control unit M60 receives a supply controlled by the ignition (INT) at pin 7 of connector A from the line protected by fuse F50 of the additional fuse box B2.

Pin 6 is connected to the specific earth C50.

When frontal impact of a certain severity (depending on the software setting) is detected, the control unit sends control signals to set off the modules:

• to driver's Air Bag Q9, via the steering wheel clockspring D47 (from pins 14 and 13 of connector A of M60):
• to passenger side air bag Q11 (from pins 15 and 16 of connector A of M60):
• to the driver's pretensioner Q20 (from pins 13 and 14 of connector B of M60) and the passenger pretensioner Q21 (from pins 15 and 16 of connector B of M60).

A signal from passenger Air Bag disabling switch H75 reaches pin 11 of connector A of M60.

The side impact detection sensors K66 (driver's side) and K67 (passenger side) send signals to pins 1, 2, 3 and 4 respectively of connector B of the control unit M60.

When side impact of a certain severity (dependent on the software setting) is detected, the control unit sends control signals to set off the modules:

• to driver's side bag Q30 (from pins 17 and 18 of connector B of M60);
• to passenger side bag Q31 (from pins 19 and 20 of connector B of M60);
• to the driver's Head Bag Q40 (from pins 21 and 22 of M60);
• to the passenger Head Bag Q41 (from pins 23 and 24 of connector B of M60).

The seat structure that houses the two side bags is connected to earth C50.

The head bags are connected to rear earths C30 and C31.

When the system self-diagnostic function detects a fault or an impact is detected, control unit M60 sends a signal -from pin 17 of connector A - to the Air Bag faulty warning light located in the instrument panel E50.; pin 12 of connector A of M60 sends the signal for the 'passenger disabling' warning light.

Self-diagnostic data can be read by connecting the unit to connector G of Body Computer M1- pin 3: this receives signals from pin 9 of connector A of control unit M60 through the relevant tester line.

Wiring diagram

Components

Component location