Seat Belt Systems: 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, 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.
All the safety belts are continuous-loop, 3-point systems. The combination lap and shoulder belt (continuous-loop) uses a common slip tongue and retractor.
The shoulder harness retractor is designed to let the webbing move freely in and out at all times, except during vehicle hard braking, hard cornering or an impact of 8 km/h (5 mph) or more, when it is automatically locked by a mechanically actuated inertia sensor.
When installing new safety belt buckles and/or retractor assemblies, use only the replacement parts specified in the Ford Customer Service Division Master Parts and Accessories Catalog.
Active Restraint System Components
The active restraint system consists of the following serviceable items:
- Front safety belt shoulder height adjusters
- Front safety belt buckle and pretensioners attached to the inboard side of the seats
- Front adaptive load limiting safety belt retractors located behind the lower B-pillar trim panels
- 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
- Rear dual safety belt buckle assembly attached to the floor pan under the LH side of the rear seat cushion
- Lower anchors and tethers for children at the rear outboard seating positions, attached below the rear seat cushion
- Rear child safety seat tether anchors welded to the parcel shelf sheet metal for all 3 rear seating positions (not serviceable separately)
Safety Belt Retractors
The safety belt retractors consist of the following features:
- Adaptive Load Limiting (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.
Safety Belt Buckles
Safety Belt Buckle and Pretensioner
The safety belt buckle and pretensioners are for the front outboard occupants and located on the inboard side of the seats. This allows the front safety belt buckle end to move with the front seat.
The safety belt buckle and pretensioner is a pyrotechnic device that removes excess webbing from the safety belt system when deployed. When the pretensioner deploys, the buckle moves downward, removing excess webbing from the lap and shoulder safety belts.
If the vehicle is involved in a crash that results in pretensioner deployment, a new safety belt buckle pretensioner must be installed.
If the ignition is ON with the safety belt buckle pretensioner electrical connector(s) disconnected, a DTC will set.
For safety belt buckle pretensioner diagnosis and disposal information, refer to Air Bag Systems.
Rear Safety Belt Buckles
The rear seat safety belt buckles are attached to the floor pan behind the rear seat cushion and can be serviced separately. After any crash, new safety belt systems components (including retractors, buckles and height adjusters) must be installed.
Child Safety Seat Restraints
The child safety seat restraints include the following items:
- Non-serviceable child safety seat tether anchors located at all 3 rear seating positions, welded to the underside of the parcel shelf sheet metal
- Serviceable lower anchors and tethers for children attachments mounted to the floor pan behind the rear seat cushion
If a child safety seat was in use during a collision, inspect the vehicle structure at the child safety seat component mounting areas and repair any damage and restore the vehicle to the original production configuration.