Pre-TENSIONERS At The Anchors

Both front seating positions are equipped with three-point seat belt systems. Both positions employ a lower B-pillar mounted inertia latch-type emergency locking retractors, height-adjustable upper B-pillar mounted turning loops, an integral anchor tensioner that is secured at the base of the B-pillar, and a traveling end-release seat belt buckle secured to the inboard side of the seat frame. The passenger side front seat belt retractor is switchable to an automatic locking retractor for compatibility with child seats.

The seat belt retractors used in all seating positions include an inertia-type, emergency locking mechanism as standard equipment.

The standard inertia-type emergency locking retractor will allow the seat belt webbing to unwind from and wind to the retractor spool freely unless, and until, a predetermined inertia load is sensed. The retractor has an internal inertia latch mechanism that will lock the retractor spool once the predetermined inertia load is sensed. Locking the retractor spool prevents the seat belt webbing from being extracted from the retractor and firmly restrains the occupant wearing the seat belt. The retractor spool is automatically unlatched once the loading of the retractor inertia mechanism and the seat belt are relieved.

The emergency locking mechanism, the retractor tensioner mechanism and the load limiting feature are each integral to the retractor unit and are concealed beneath molded plastic covers located on each side of the retractor spool. These features cannot be adjusted or repaired and if ineffective, damaged or deployed, the entire seat belt and retractor unit must be replaced.

The buckles of the driver and front passenger seats are equipped with a Hall-effect sensor that checks the seat belt fastening. The Hall-effect sensors are hardwired to, and monitored by, the ORC.

A 1.0 kilohm diagnostic resistor is connected in parallel with the Hall-effect sensor where the two pigtail wire leads connect to the Hall-effect sensor terminals. The resistor allows a small amount of current to flow through the circuit continuously. The ORC monitors the current in the circuit. When 5-8 mA are present, the seat belt is unbuckled. When 12-17 mA are present, the seat belt is buckled. If the harness is disconnected, the current flow is interrupted and a seat belt switch Diagnostic Trouble Code (DTC) is set.

The front seat belt switches are designed to control a hardwired switch status input to the ORC. A spring-loaded slide with a small window-like opening is integral to the buckle latch mechanism. When a seat belt tip-half is inserted and latched to the seat belt buckle, the slide is pushed downward and the window of the slide exposes the Hall Effect integrated circuit chip within the buckle. The field of the permanent magnet induces a current within the chip. The chip provides this induced current as an output to the ORC. When the seat belt is unbuckled, the spring-loaded slide moves upward and shields the integrated circuit from the field of the permanent magnet, causing the output current from the seat belt switch to be reduced.

The seat belt switches receive a supply of current from the ORC, and the ORC senses the status of the seat belt switches through its connection to each switch. The ORC provides electronic seat belt switch status messages to the IPC over the CAN data bus. The IPC uses these messages as an additional logic input for control of the seat belt indicator. The ORC monitors the condition of the seat belt switch circuits and will store a DTC for any fault that is detected.

The seat belt switches cannot be adjusted or repaired and, if ineffective or damaged, the entire front seat belt buckle-half unit must be replaced. Refer to BUCKLE, SEAT BELT, REMOVAL AND INSTALLATION .