Automatic Belt Retractor, Checking

The automatic belt retractor has two locking functions. 

• The first locking function is initiated by the belt being jerked out of the belt retractor (belt extraction acceleration).

Test 1 

-- Pull the belt webbing out of the belt retractor with a firm jerk.

• No locking effect - replace seat belt complete with belt buckle.
• If difficulties are experienced when pulling out or retracting belt, first check whether position of the belt retractor has been altered.
• The second locking function is initiated by change in vehicle velocity (vehicle-dependent locking function).

Test 2 

-- Fasten seat belt.

-- Accelerate vehicle to 20 km/h and then perform a full braking maneuver with foot brake.

• Replace seat belt complete with seat belt latch if seat belt is not locked by locking mechanism during braking procedure.