AIRBAG - Functional description

Functional description

The Air Bag system control unit M60 receives a supply controlled by the ignition (INT) at pin 12 of connector A from the line protected by fuse F50 of the additional fuse box B2.

Pin 1 of connector A and pin 17 of connector B are connected to a specific earth C50.

Early crash sensor K39 detects slight bumps and reports them to control unit M60 - pins 2 and 4 of connector A of M60.

Occupant classification sensor K65 records the weight and size of the front passenger seat occupant: the sensor is supplied by a line protected by fuse F50 of underfacia control unit B2, and sends a signal to pin 19 of connector B 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 23 and 24 of connector A of M60 ):
• to passenger side air bag Q11 (from pins 21 and 22 of connector A of M60 ):
• to the pretensioners on the driver's side Q20 (from pins 1 and 2 of connector B of M60 ) and the passenger side Q21 (from pins 3 and 4 of connector B of M60 ).
• to driver side rear pretensioners Q22 (from pins 15 and 16 of connector A of M60 ) and passenger side Q23 (from pins 13 and 14 of connector A 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 19 and 20 of connector A of M60 ):
• to passenger side air bag Q11 (from pins 17 and 18 of connector A of M60 ):

Pin 11 of connector A of M60 receives a signal from passenger air bag disablement switch H75, supplied from pin 10 of connector A of M60.

The side impact detection sensors K66 (driver's side) and K67 (passenger side) send signals to pins 24, 26, 25 and 27, 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 6 and 5 of connector B of M60 );
• to passenger side front air bag Q31 (from pins 9 and 10 of connector B of M60 );
• to driver's rear side bag Q43 (from pins 13 and 14 of connector B of M60);
• to passenger side rear air bag Q42 (from pins 15 and 16 of connector B of M60 );
• to the driver's Head Bag Q40 (from pins 7 and 8 of connector B of M60 );
• to the passenger Head Bag Q41 (from pins 12 and 11 of connector B of M60 ).

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

A signal from passenger Air Bag disabling switch H76 reaches pin 30 of connector B of M60 supplied by pin 31 of connector B of M60

Switches on front seat belts I45 and I46 inform the control units if any seat belts are unfastened, by connecting to pins 20, 22 and 21, 23 of connector B of M60.

When the system self-diagnostic function detects a fault or an impact is detected, control unit M60 sends a signal -from pin 8 of connector A - to the Air Bag faulty warning light located in the instrument panel E50 .; pin 7 of connector A of M60 sends the signal for the 'passenger disabling' warning light. pin 23 of connector B sends a rear air bag disablement warning lgiht signal, and lastly pin 9 of connector A of M60 sends a seat belt unfastened warning light signal.

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.

The crash signal from pin 5 of connector A of the control unit M60 is sent to pin 13 of connector F of the integrated radio-telephone-navigator P20.