Seat Belt Systems: Description and Operation
Safety Belt System
COMPONENT LOCATION
OVERVIEW
A 3 point safety belt is installed in all seating positions. Each seatbelt has emergency locking retractor functionality.
The emergency locking retractor function incorporates a lift shaft locking system with webbing sensor and car sensing activating mechanisms. The webbing sensor activates the locking mechanism if the webbing is subjected to a sharp pull. The car sensor activates the locking system if the vehicle is subjected to sudden deceleration or severe tilt angle.
All row 1 driver and passenger emergency locking retractor incorporate an electrically activated webbing tension reducer (comfort device). This device is activated when the vehicle enters ignition mode 6 and insertion of the seatbelt tongue into the buckle.
All row 2 passengers and NAS front Passenger emergency locking retractors are enhanced with automatic locking retractors.
The automatic locking retractor allows webbing to be extracted to activate a ratchet device. This device allows webbing to be cinched tight to facilitate child seat fitment. With seatbelt webbing tensioned in automatic locking retractor mode the seatbelt is always locked.
A safety belt warning indicator is installed in the instrument cluster to remind the front seat occupants to fasten their safety belts. On North American Specification (NAS) vehicles, when the ignition mode is accessory/convenience, the warning indicator illuminates if the safety belt of an occupied front seat is not fastened. The warning indicator remains illuminated until the safety belt of each occupied front seat is fastened, or the ignition mode is off. In all markets except NAS, a belt minder function provides a more intrusive reminder to fasten the front safety belts.
Belt Minder Function
The belt minder function provides warnings to the driver if the appropriate front safety belts are not fastened when driving. The belt minder function is controlled by the instrument cluster using:
^ High speed CAN (controller area network) bus messages, from the RCM (restraints control module), to monitor the status of the front safety belts.
^ An input from the occupant detection system to monitor the status of the front passenger seat.
When the ignition is switched to on, the instrument cluster illuminates the safety belt warning indicator until one of the front safety belts is fastened or the belt minder function is triggered. The belt minder function is triggered when the ignition switch is in accessory/convenience and the following conditions coexist:
^ The belt minder function is enabled
^ The vehicle is not in reverse
^ Vehicle speed is 8 km/h (5 mph) or more
^ The driver safety belt or, if the front passenger seat is occupied, the front passenger safety belt, is unfastened.
When the belt minder is triggered, the instrument cluster generates the following warnings for 10 seconds.
^ Flashes the safety belt warning indicator at 2 Hz
^ Sounds a repeating chime in sequence with the flashing safety belt warning indicator.
After 10 seconds, the repeating chime is discontinued and the safety belt warning indicator changes from flashing to continuously illuminated for 20 seconds. While the trigger conditions still coexist, the warnings are repeated every 30 seconds until one of the following occurs:
^ 5 minutes has elapsed from when the warnings were first triggered
^ The safety belt of each occupied front seat is fastened
^ The ignition mode is position 0
^ The vehicle speed decreases to 5 km/h (3 mph).
For non NAS vehicles the belt minder function can be enabled and disabled using the driver safety belt switch. The instrument cluster changes the state of the belt minder function if, within 60 seconds of first entering ignition mode II, the driver safety belt is fastened and unfastened nine times. Successful completion of the change is indicated by a single chime and the safety belt warning indicator flashing five times, at 2 Hz. The belt minder function can also be enabled and disabled using the recommended Land Rover diagnostic tool.
Safety Belt Warning Indicator
SECOND ROW SAFETY BELTS
The retractor of each outboard second row safety belt is attached to the body immediately behind the D pillar. The webbing runs from the retractor, through an upper mounting on the D pillar, to an anchor point at the front of the related wheel arch.
The retractor for the center second row safety belt is installed in the top of the seat back. The webbing runs from the retractor, over the top of the seat, to an anchor point at the base of the seat frame.
The buckles for the second row safety belts are attached to the related seat frame.