Seat Belt Tensioner: Description and Operation
Safety Belt System
WARNING: After any crash, all of the following safety belt assemblies and attaching hardware must be inspected by an authorized dealer to verify correct function:
- Retractors
- Buckles
- Belt tension sensor (BTS) (if equipped)
- Front safety belt buckle support assemblies (slide bar) (if equipped)
- Safety belt shoulder belt height adjusters (if equipped)
- Child safety seat tether bracket assemblies
- Automatic locking retractor (ALR) feature for child safety seats (passenger seating positions only)
If any safety belt assembly is damaged, does not operate correctly or does not pass all of the Functional Tests in the Diagnosis and Testing portion, a new safety belt assembly must be installed. If any safety belt assembly attaching areas are damaged or distorted, the sheet metal must be restored to its original structural integrity and new safety belt assembly and attaching hardware must be installed. Failure to install new safety belt assemblies and attaching hardware may increase the risk of serious personal injury or death in a crash.
After any crash that results in deployment of the driver and/or front outboard passenger safety belt pretensioners, new driver and/or front outboard passenger safety belt systems (including retractors, buckles and height adjusters) must be installed. Failure to install new safety belt systems increases the risk of serious personal injury or death in a crash.
When replacing any active occupant restraint components, use only the replacement parts specified in the Ford Customer Service Division Master Parts Catalog.
The active restraint system consists of the following:
- Front safety belt shoulder height adjusters
- Front row safety belt buckle and pretensioners attached to the inboard side of the seats
- Front row adaptive load limiting safety belt retractors located behind the lower B-pillar trim panels
- Second row and third row outboard safety belt retractors located behind the quarter trim panels (Taurus X)
- Second row 60/40 seat center safety belt retractor and LH safety belt buckle assembly integrated into the 60 percent seat back (Taurus X)
- Rear center safety belt retractor attached to the parcel shelf sheet metal and safety belt buckle assembly attached to the floor pan under the rear seat cushion (Taurus, Sable)
- Second row dual safety belt buckle assembly attached to the floor pan under the LH seat cushion (Taurus, Sable)
- Second row safety belt buckle assembly attached to the seat frame (Taurus X)
- Third row safety belt buckle assembly attached to the seat frame (Taurus X)
- Lower anchors and tethers for children at all 3 rear seating positions, attached below the rear seat cushion (Taurus, Sable)
- Lower anchors and tethers for children located at the second row outboard seating positions and third row RH seating position, all welded to the seat cushion frame (Taurus X)
- The child safety seat tether anchors are welded to the parcel shelf sheet metal for all 3 rear seating positions (Taurus, Sable)
- Child safety seat tether anchors located at the front passenger seating position, second row outboard seating positions and third row RH seating positions all welded to the seat cushion frame (Taurus X)
Safety Belt Retractors
The safety belt retractor consists of the following:
- Adaptive load limiting retractor (front only)
- Dual locking mode
- Emergency Locking Retractor (ELR)
- Automatic Locking Retractor (ALR) (all except driver seat)
- Belt Tension Sensor (BTS) (front passenger only)
Adaptive load limiting
Adaptive load limiting safety belt retractors are pyrotechnic devices integrated with the driver and front passenger safety belt retractor assemblies. Adaptive load limiting safety belt retractors work in conjunction with the safety belt buckle pretensioners to control the tension of the driver and front passenger safety belts. The Restraints Control Module (RCM) monitors the readiness of the adaptive load limiting safety belt retractor. The RCM uses this information and all other information provided by the restraints system to determine what action is to be taken.
For adaptive load limiting safety belt retractor diagnostic information, refer to Air Bag Systems.
Automatic Locking Retractor (ALR)
The ALR mode is used when locking a child seat in an outboard seating position. The ALR mode is automatically activated when the safety belt webbing is fully extracted from the retractor and then allowed to retract. As the safety belt webbing is retracted back onto the spool, an audible clicking sound is made indicating the safety belt retractor is in ALR mode and the safety belt webbing will not pull back out of the safety belt retractor. To disengage the ALR mode, allow the safety belt webbing to fully retract back onto the spool. The ALR mode is disengaged when the webbing is free to extract and retract back into the retractor. For testing, refer to the appropriate Functional Test procedure in Safety Belt System Component Tests and General Diagnostics.
Emergency Locking Retractor (ELR)
The ELR is a vehicle-sensitive feature designed to activate and lock the safety belt webbing during hard braking, cornering hard or in an impact of approximately 8 km/h (5 mph). The ELR feature helps to reduce the forward movement of the driver and passengers. For testing, refer to the appropriate Functional Test procedure in Safety Belt System Component Tests and General Diagnostics.
Belt Tension Sensor (BTS)
The BTS is located at the safety belt anchor point and operates as part of the Occupant Classification Sensor (OCS) system on the front passenger seat. To diagnose the BTS or OCS system, refer to Air Bag Systems.