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 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 Component Tests, 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.

Use only the replacement parts specified in the Ford Catalog Advantage(TM) or equivalent when installing new safety belt buckles and/or retractor assemblies.

Active Restraint System Components

The active restraint system consists of the following serviceable items:

- Front safety belt shoulder height adjusters
- Front safety belt buckles attached to the inboard side of the seats
- Front safety belt retractors and pretensioners (pretensioner feature available only on vehicles equipped with Supplemental Restraint System (SRS)) located behind the lower B-pillar trim panels
- Rear center safety belt retractor attached to the parcel shelf sheet metal (4-door sedan) or LR seat frame (5-door hatchback) and LH safety belt buckle assembly attached to the floor pan under the rear seat cushion
- Rear safety belt retractors (outboard) attached to the parcel shelf sheet metal (4-door sedan) or C-pillars (5-door hatchback)
- Rear dual safety belt buckle assembly (RH and center safety belt buckles) attached to the floor pan
- Child safety seat tether anchors located on the parcel shelf (4-door sedan) or on the back of the second row seat back rest (5-door hatchback), at all 3 seating positions
- Lower Anchors and Tethers for Children (LATCH) attached to the floor pan

Safety Belt Retractors

The safety belt retractors consist of the following components:

- Safety belt retractor pretensioner (front only), on vehicles equipped with SRS
- Adaptive load limiting (front passenger only), on vehicles equipped with SRS
- Dual locking mode
- Emergency Locking Retractor (ELR)
- Automatic Locking Retractor (ALR) (all except driver seat)

- Belt Tension Sensor (BTS) (front passenger only), on vehicles equipped with SRS

Automatic Locking Retractor (ALR)

The ALR mode is used when locking a child seat in any passenger seating position. The ALR mode automatically activates when the safety belt webbing is fully extracted from the retractor and then allowed to retract. As the safety belt webbing retracts 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. The ALR mode disengages when the webbing is allowed to fully retract back into the retractor. For testing, refer to the appropriate Functional Test procedure in Safety Belt System Principles Of Operation.

Safety Belt Retractor Pretensioner

The safety belt retractor pretensioner is a pyrotechnic device that removes excess webbing from the safety belt system when deployed by the SRS. When the pretensioner deploys, the retractor spools in the safety belt webbing, removing excess webbing from the lap and shoulder safety belts.

If the vehicle is involved in a crash resulting in pretensioner deployment, install a new safety belt retractor pretensioner. For safety belt retractor pretensioner diagnosis and disposal information, refer to Supplemental Restraint System Testing and Inspection.

If the ignition is ON with the safety belt retractor pretensioner electrical connector(s) disconnected, a DTC sets.

The pretensioner feature is only available on the front safety belt retractors of SRS-equipped vehicles.

Adaptive Load Limiting

Adaptive load limiting safety belt retractors are pyrotechnic devices integrated with the front passenger safety belt retractor assembly. The adaptive load limiting safety belt retractor works in conjunction with the safety belt pretensioner to control the tension of the front passenger safety belt. 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.

The adaptive load limiting pyrotechnic device feature is only available on the front passenger safety belt retractors of SRS-equipped vehicles.

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 24 km/h (15 mph). The ELR feature helps reduce the forward movement of the driver and passengers. For testing, refer to the appropriate Functional Test procedure in Safety Belt System Principles Of Operation.

Belt Tension Sensor (BTS)

The BTS is located at the front passenger safety belt retractor anchor point and operates as part of the Occupant Classification System (OCS) system on the front passenger seat. To diagnose the BTS, refer to Supplemental Restraint System Testing and Inspection.

Safety Belt Buckles

Front Safety Belt Buckles

The front seat safety belt buckles are attached to the front seat tracks.

On vehicles equipped with an SRS, the front safety belt buckles have a switch indicating buckle status to the RCM. To diagnose the buckle switch, refer to Supplemental Restraint System Testing and Inspection.

Rear Safety Belt Buckles

The rear seat safety belt buckles are attached to the floor pan under the rear seat cushion. The LH safety belt buckle is part of the rear center safety belt retractor and is serviced as an assembly. The rear dual safety belt buckle assembly (RH and center buckle) is also serviced as an assembly.

Child Safety Seat Restraints

The child safety seat restraints include the following items:

- Serviceable child safety seat tether anchor located at the rear seating positions, bolted to the parcel shelf sheet metal on 4-door sedans. On 5-door hatchbacks, the child safety seat tether anchors are part of the second row seat back and are not serviced separately from the seat back.
- Non-serviceable Lower Anchors and Tethers for Children (LATCH), welded to the floor pan.

If a child safety seat was in use during a collision, inspect the vehicle structure at the child safety seat component mounting areas, repair any damage and restore the vehicle to the original production configuration.