SRS Description

The Supplementary Restraint System (SRS) provides additional protection for front seat occupants during a frontal collision above a preset severity.

The system is operational only with the ignition switch in position II. With the ignition on, any frontal collision is detected by an accelerometer and a mechanical safing sensor within the airbag DCU. If the impact is above the preset severity, the airbag DCU transmits simultaneous signals to fire the airbag modules and seat belt pretensioners. The airbag modules deploy protective airbags in front of the driver and front seat passenger and the seat belt pretensioners retract to tighten the front seat belts.

The airbag DCU can store fault codes for the DCU, the driver and passenger airbag modules and the pretensioners. These fault codes can be accessed using TestBook via the diagnostic socket.

The airbag DCU is located below the center console near the hand brake mounting. The driver airbag is located in the center of the steering wheel and the passenger airbag is located in the fascia, above the glovebox. The seat belt pre-tensioners are located with the seat belt anchorages.

An SRS warning LED is located in the instrument pack. When the ignition switch is turned to position II, the LED will be illuminated for 3 to 5 seconds to confirm LED operation. If a fault in the SRS system occurs, the LED will be illuminated for the duration of the fault or for a period of between 8 to 16 seconds.

The airbag DCU can supply a low voltage test current to the airbags and pre-tensioners to check circuit continuity. The DCU can also detect shorts, shorts to ground or battery and open circuits. These conditions can be retrieved using TestBook.


! WARNING: Never use multimeters or other general purpose test equipment on SRS system components or connectors. System faults should be diagnosed through the use of recommended test equipment only.


SRS Supply
Circuit supply
A feed from the battery positive terminal is connected on an R wire to the engine compartment fusebox where it passes through fusible link 8.

A feed from fusible link 8 is connected on an NW wire to the passenger compartment fusebox and from the fusebox to the ignition switch (5176) on an N wire.

Ignition switch supply
With the ignition switch in position II the feed from fusible link 8 passes through the ignition switch to the passenger compartment fusebox on a Y wire. The feed continues through fuse 35 in the passenger compartment fusebox and is connected from the fusebox to the airbag DCU on G wire.

A second feed from fuse 35 is connected on a G wire to the SRS warning lamp in the instrument pack. The SRS warning lamp is connected from the instrument pack to the airbag DCU on a YR wire. If a failure of the LED or connecting wiring occurs, the airbag DCU detects a O V condition on the YR wire and stores a fault code in the DCU memory.

The airbag DCU is connected to earth eyelet connector C0360-1 on a B wire.