General information
All models discussed in this manual are equipped with an additional security system (SRS), better known as airbags. In the mandatory configuration of models since 1995, no. two airbags included. The system provides additional protection for the driver and front passenger of the car in the event of a severe frontal impact. On models of early years of production, only the driver's airbag is provided. The SRS control unit includes a self-diagnosis module. The SRS ECU is located inside the vehicle.
Models 1998 and 1999 issue additionally equipped with side airbags for the front seats, which are activated in case of severe side impacts.
The airbags are deployed by directional g-force sensor signals processed by the SRS ECU.
Airbag modules
Driver airbag
The module is placed in the hub part of the steering wheel and consists of a casing, inside of which the pillow itself and the gas generating unit are placed. The gas generator is located at the rear of the casing and provides almost instantaneous filling of the bag with gas on command issued by the SRS. An electrical signal is supplied to the gas generator through a spring contact mounted in the hub of the steering column behind the airbag module.
The signal is transmitted via a spring contact regardless of the position of the steering wheel. An igniter inside the gas generator assembly converts the incoming command into a thermal pulse, causing ignition of a powdered mixture of sodium azide with copper oxide. During the explosive combustion of the powder, nitrogen is released, filling the airbag in a fraction of a second.
Passenger airbag
The passenger airbag module is mounted in the vehicle's instrument panel directly above the glove box. In this case, the marking is applied on top of the instrument panel "SRS". The composition and principle of operation of the module are similar to those discussed above for the driver's airbag.
The passenger airbag is slightly larger than the driver airbag and is equipped with a steel thrust casing. The decorative cover is separated by a sealed seam that diverges when the system is triggered.
Side airbags
With a more compact design, side airbags provide protection for the driver and front passenger in severe side impacts of the vehicle. The side airbag overload sensors are located at the bottom of the door pillars.
Control unit / self-diagnostics and additional overload sensors
The SRS control / self-diagnosis unit consists of a microprocessor that monitors the parameters of the system and an overload sensor. The system informs the driver about the identified problems by turning on the warning lamp. At the same time, the corresponding fault code is entered into the processor memory. The car in such a situation should be immediately driven to a service station. The indicator lamp will remain lit until the processor memory has been cleared after performing the appropriate remedial repair. On most models, the SRS control unit is located under the rear of the center console, but can also be installed under the instrument panel.
The airbag is activated only when the main and additional sensors of directional overloads are activated simultaneously. In the event of a battery failure, power is supplied to the SRS system from an independent backup source.
Precautionary measures
Warning! Failure to follow the precautions for handling SRS components can result in serious injury!
When servicing all components in the vicinity of the airbags, always deactivate the SRS first:
When removing airbag modules, always keep them facing away from you. Do not place the module on a workbench or other surface with the airbag opening down.
NEVER use an ohmmeter to measure the resistance of SRS components, voltage from the power source built into the meter can cause the airbags to deploy.
Be sure to disconnect the SRS wiring before using arc welding on a vehicle (yellow connector located under the steering column next to the connector for the combined steering column switch - driver's airbag) and the same connector behind the glove box assembly (passenger airbag).
Disabling the SRS system
Disconnect the negative cable first, then the positive cable from the battery and wait at least 10 minutes before proceeding with the procedures.
Attention! If the stereo system installed in the car is equipped with a security code, before disconnecting the battery, make sure that you have the correct combination to activate the audio system!
Driver airbag
Remove the access panel in the center of the steering wheel under the airbag module assembly and disconnect the 2-pin connector of the wiring harness going between the module and the spring contact (see chapter Suspension and steering).
Passenger airbag
Open the glove box.
At the top of the storage compartment, near the latch, disconnect the 2-pin connector of the yellow wiring harness connecting the airbag module to the main cable.
Side airbags
Prying off with a special tool, carefully separate the rear trim panel of the corresponding front seat - try not to touch the yellow wiring.
Disconnect the wiring connector.
Activating the SRS system
Switching on the SRS modules is done in the reverse order.
Switch off the ignition.
Connect the battery.
Removal and installation of SRS components
Driver airbag
see chapter Suspension and steering.
Passenger airbag
Deactivate the relevant airbag module.
Remove the lower trim section from the passenger side of the instrument panel (see chapter Body).
Disconnect the 2-pin electrical connector. Unscrew the sealed TORX head bolts, then, carefully prying with a screwdriver, separate the airbag module from the instrument panel.
Attention! The module is heavy - hold it with two hands
Installation is in the reverse order.
Note. The module mounting bolts must be replaced without fail.
Side airbags
Disable the SRS system.
Disconnect the wiring harness connector for the relevant airbag module. Remove the two TORX mounting screws and remove the module.
Installation is in the reverse order.