Ford Fiesta Quiz
Body and Paint

Seat Belt Systems - Diagnosis and Testing

In this manual: Body and Paint
Service Information — 27Suspension — 48Transmission — 9Brake System — 52Steering — 21Engine — 140Manual Transmission, Clutch, Transfer Case and Power Transfer Unit — 48Exhaust System — 6Fuel System — 21Climate Control System — 58Instrumentation and Warning Systems — 26Battery and Charging System — 20Infotainment Systems — 41Lighting — 29Power Distribution — 11Electronic Function Group — 30Body and Paint — 275Frame and Mounting — 3
21steps
~126min
5/5difficulty
Done 0 of 21

Symptom Chart

Preliminary Inspection

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).

Before diagnosing or repairing the seat belt system, check the following:

  • Seat belt webbing integrity (torn, frayed, cut or stretched)
  • Seat Belt Buckle and Tongue Assembly

Symptom Chart: Seat Belt System

Symptom Chart


Condition Possible Sources Action
Unbuckled seat belt warning indicator does not work
  • Malfunction Indicator
  • Wiring, Terminals or Connectors
  • PCM
  • RCM
 If the airbag indicator does not illuminate,
Refer to: Instrument Cluster, Message Center and Warning Chimes (413-01 Instrument Cluster, Message Center and Warning Chimes, Diagnosis and Testing).
Unbuckled seat belt chime does not work
  • Wiring, Terminals or Connectors
  • seat belt switch
  • PCM
  • RCM
 If the airbag indicator is illuminated,
Refer to: Supplemental Restraint System (SRS) (501-20 Supplemental Restraint System).
If the airbag warning indicator does not illuminate, refer to Instrument Cluster, Message Center and Warning Chimes (413-01 Instrument Cluster, Message Center and Warning Chimes, Diagnosis and Testing).
Seat belt webbing does not extend or applies excessive pressure to the occupant during use
  • Seat belt retractor is in web sensing mode
 RELEASE the locked seat belt retractor.
Refer to: Releasing a Locked Seat Belt Retractor (501-20A Seat Belt Systems, General Procedures).
  • Interior trim installed incorrectly
 CORRECT the trim panel installation. Refer to Section 501-05.
  • The seat belt retractor is in Automatic Locking Retractor (ALR) mode.
  • Seat belt retractor with internal jam
 PERFORM the appropriate functional test. Refer to Functional Test - Seat Belt Pretensioner, Functional Test - Seat Belt Retractor, Automatic Locking Retractor (ALR) Mode, or Functional Test - Seat Belt Retractor, Road Test, as applicable. INSTALL new components as necessary.
Seat belt webbing does not retract or excessively slackens during use.
  • Seat belt webbing twisted or routed incorrectly
 CORRECT the twisted seat belt webbing.
Refer to: Seat Belt Tongue Rotates on Belt (501-20A Seat Belt Systems, General Procedures).
Refer to: Seat Belt Tongue Rotates on Belt (501-20A Seat Belt Systems, General Procedures).
  • Interior trim installed incorrectly
 CORRECT the trim panel installation. Refer to Section 501-05.
  • Seat belt retractor with internal jam
 PERFORM the appropriate functional test. Refer to Functional Test - Seat Belt Pretensioner, Functional Test - Seat Belt Retractor, Automatic Locking Retractor (ALR) Mode, or Functional Test - Seat Belt Retractor, Road Test, as applicable. INSTALL new components as necessary.
Belt-Minder® feature does not function
  • Belt-Minder® Function Deactivated
  • Wiring, Terminals or Connectors
 Activate the Belt-Minder® function.
REFER TO: Belt-Minder® Deactivation/Activation (413-01 Instrument Cluster, Message Center and Warning Chimes, General Procedures).
If the Belt-Minder® is activated, CHECK the non-functioning Belt-Minder® function. Refer to: Instrument Cluster, Message Center and Warning Chimes (413-01 Instrument Cluster, Message Center and Warning Chimes, Diagnosis and Testing).
Seat belt latch plate rotates on the seat belt webbing. Seat belt webbing twisted or routed incorrectly
Refer to: Seat Belt Tongue Rotates on Belt (501-20A Seat Belt Systems, General Procedures).
Seat belt webbing is twisted in the seat belt guide. Seat belt webbing twisted or routed incorrectly
Refer to: Seat Belt Twisted in Seat Belt Guide (501-20A Seat Belt Systems, General Procedures).
Seat belt webbing is dirty or soiled Seat belt webbing dirty or soiled
Refer to: Cleaning Seat Belts (501-20A Seat Belt Systems, General Procedures).

Functional Test - Seat Belt Buckle and Tongue

  1. During the latching sequence, check the following:
  • Tongue insertion does not require excessive force.
  • A click is heard when the buckle latches onto the tongue.
  1. Check the system integrity by pulling firmly on the seat belt webbing.
  2. Unfasten the seat belt by fully pressing the seat belt buckle release button and allowing the seat belt to unlatch and retract.
  3. During the unlatching process, check the following:
  • Button press does not require excessive force.
  • The tongue releases easily from the buckle.
  1. Repeat the above steps 3 times.
  2. If the functional check reveals a fault, install a new seat belt buckle or seat belt retractor as necessary.

Functional Test - Seat Belt Retractor

  1. Extend and retract the seat belt webbing between the fully extended and stowed positions.
  2. Make sure the seat belt retractor operates without excessive force or binding.
  3. Install a new seat belt retractor if any problems are found or the customer complaint is confirmed.

Functional Test - Seat Belt Retractor Mode, Automatic Locking Retractor (ALR)

  1. Position the seatback upright (if adjustable).
  2. Set the seat belt shoulder height adjuster (if equipped) to the lowest or highest position.
  3. Fasten the seat belt.
  4. Pull out the seat belt webbing until the Automatic Locking Retractor (ALR) function is activated.
  5. Allow the seat belt to retract fully.
  6. Pull the seat belt webbing to make sure the seat belt retractor remains in Automatic Locking Retractor (ALR) mode. If the seat belt retractor does not lock, install a new seat belt retractor.
  7. Unlatch the seat belt and allow the webbing to retract to its original position.
  8. Extend and retract the seat belt webbing to check that the seat belt retractor automatically returns from Automatic Locking Retractor (ALR) mode. If the seat belt retractor remains locked in Automatic Locking Retractor (ALR) mode, install a new seat belt retractor.

Functional Test - Seat Belt Retractor, Road Test Inspection

  1. Fasten the seat belts and proceed to a safe area.
  2. Accelerate to 24 km/h.
  1. Grasp the shoulder belt, lean forward and apply the brakes, braking as hard as possible without skidding.
  2. Seat belts must latch with minimal webbing tension.
  3. If all seat belt retractors lock, verify that the seat belt retractors operate correctly. If any seat belt retractor does not lock, install new seat belt retractor(s).

Test yourself

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