Car MOT Manual 2012 onwards
Seat Belts and Supplementary Restraint Systems - 5.4 Supplementary Restraint Systems SRS
The SRS malfunction indicator lamp MIL may display a symbol similar to that shown below, or one depicting a person wearing a seat belt. Alternatively, the letters SRS or another symbol may be displayed.
Seat belt load limiters are used on some vehicles to minimise seat belt inflicted injury in violent collisions. This is generally achieved by releasing a little more excess belt webbing when a great deal of force is applied to the belt. The simplest type of load limiter is a fold sewn into the belt webbing. The stitches holding the fold in place are designed to come apart when a high amount of force is applied to the belt, thereby releasing an extra bit of webbing. A more commonly used limiter is a mechanical type, such as those which use a torsion bar in the retractor mechanism. These cannot usually be readily seen or inspected.
Seat belt pretensioners may be fitted to some seat belts. Once activated a warning device may display.
2. Turn on the ignition and check the presence and operation of any Supplementary Restraint System SRS malfunction indictor lamps MIL.
3. Check the presence and condition of any seat belt load limiters and/or pretensioners fitted as original equipment
2. A Supplementary Restraint System SRS malfunction indicator lamp:
• indicating a system malfunction.
a. A seat belt load limiter or pretensioner obviously missing where fitted as original equipment
b. a seat belt pretensioner or a folded webbing type load limiter obviously deployed.