AIRBAG - Functional description

Functional description

The Air Bag system control unit M60 receives a supply controlled by the ignition (INT) at pin 8 of connector A from the line protected by fuse F50 of the junction unit under the dashboard B2.

Pin 16 of connector A is connected to the special earth C50.

Early crash sensor K39 detects slight bumps and reports them to control unit M60 - pins 5 and 6 of connector A of M60.

When a frontal impact of a certain severity (depending on the control strategy, data from the above two sensors and sensors incorporated in the control unit) is detected, the control unit sends control signals for stage 1 operation of the front modules:

to driver's Air Bag Q9, via the steering wheel clockspring D47 (from pins 21 and 22 of connector A of M60):

to the passenger Air Bag Q11 (from pins 23 and 24 of connector A of M60);

to the pretensioners on the driver's side Q20 (from pins 9 and 11 of connector B of M60) and the passenger side Q21 (from pins 10 and 12 of connector B of M60);

When frontal impact of a certain severity is detected, the control unit sends control signals to set off the stage 2 front modules:

• to driver's Air Bag Q9, via the steering wheel clockspring D47 (from pins 17 and 18 of connector A of M60);
• to passenger side Air Bag Q11 (from pins 19 and 20 of connector A of M60);

A signal from passenger Air Bag disabling switch H75 reaches pin 4 of connector A of M60, supplied by pin 10 of connector A of M60

The side impact detection sensors K66 (driver's side) and K67 (passenger side) send signals to pins 9 and 10, 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 front Air Bag Q30 (from pins 23 and 24 of connector B of M60);
• to passenger side front Air Bag Q31 (from pins 21 and 22 of connector B of M60);
• to the driver's Head Bag Q40 (from pins 17 and 18 of connector B of M60);
• to the passenger Head Bag Q41 (from pins 19 and 20 of connector B of M60).

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

When the system self-diagnostic function detects a fault or an impact is detected, control unit M60 sends a signal -from pin 15 of connector A - to the Air Bag faulty warning light located in the instrument panel E50.; pin 11 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 C of Body Computer M1 - pin 3: it arrives via the special diagnostic line from pin 7 of connector A of M60