Seat Belt, Checking
Seat Belts, Checking
CAUTION: After every accident the seat belt system must be inspected systematically. If damage is determined when inspecting the check points, customer must be informed regarding necessity of changing belts.
Check points:
- Check belt strap.
- Check belt retractor (locking action).
- Visual inspection of belt buckle
- Functional test of belt buckle
- Check belt guides and latch plate
- Check securing parts and anchorage points
NOTE: If customer refuses to have a damaged seat belt replaced, appropriate note should be made.
Seat Belts
Checking belt
- Pull belt as far as it will go out of belt retractor or lap belt adjuster.
- Check belt for dirt and wash if necessary with a mild soap solution.
- If either of the following types of damage (1 and 2) illustrated below is found on a vehicle following an accident, replace seat belt complete with buckle.
- If damage such as illustrated by items 1, 2 or 3 is found on a vehicle which has not been involved in an accident, only the damaged seat belt has to be replaced.
- 1 Belt cut, torn or chafed
- 2 Frayed fabric at edge of belt
- 3 Burn marks caused by cigarettes or the like
Belt retractor (locking action), checking
The belt retractor has two locking functions.
- The first locking function is triggered by pulling belt quickly out of belt retractor (accelerated belt unwinding).
Checking
- Pull belt firmly out of belt retractor.
- If there is no locking effect, replace seat belt complete with buckle.
- In the event of problems with belt unwinding or retraction, start by checking whether position of belt retractor has changed.
- The second locking function is triggered by altering vehicle motion (vehicle-dependent locking function).
Checking
- Fasten seat belt.
- Accelerate vehicle to 20 km/h and then press foot brake to implement emergency braking.
- If braking does not cause belt to lock by locking mechanism, replace seat belt complete with buckle.
CAUTION: For safety reasons, test drive is to be performed on a road with no traffic so as not to endanger other road users.
Visual inspection of buckle
- Examine buckle for cracks and chipping.
- If damage, replace seat belt complete with buckle.
Checking operation of buckle
Checking buckle:
- Insert latch plate in buckle until it is audibly engage. Pull firmly on belt to check whether locking mechanism has engaged.
- If latch plate fails to lock even once in the course of at least 5 test operations, replace seat belt complete with buckle.
Checking release function:
- Release seat belt by pressing buckle button with finger.
- Latch plate must be automatically ejected from buckle when webbing is loose.
- Check at least 5 times. If latch plate fails to be ejected even once, replace seat belt complete with buckle.
CAUTION: Never use lubricant to eliminate noise or stiffness at buckle buttons.
Checking guide fittings and latch plate
If belt system has been subjected to load (seat belt fastened in an accident), plastic-coated fittings will reveal fine parallel score marks (in contrast, wear induced by frequent use can be seen from a smooth surface with no score marks).
- Examine plastic for deformation, chipping and cracks.
- In the event of score marks and/or damage, replace seat belt complete with buckle.
Checking attachment components and anchorage points
- Latch plate deformed (elongated)
- Height adjuster not working
- Anchorage points (seat, pillar, floor) deformed or thread damaged
- If component is damage, replace seat belt complete with buckle.
- Replace anchorage points.
NOTE: Only the damaged component has to be replaced in the event of damage not resulting from an accident (e.g. wear).
Child-seat Restraint Function For Additional Child Seats (not For Drivers Seat Belt), Checking
- The complete belt assembly (including side panel trim) must be installed when checking this function.
- Activation of restraint function:
- Pull out webbing as far as possible.
- Correct function:
- The belt should retract with an audible noise.
- If the belt retraction is stopped, it should not be possible to pull the belt out again until the function is deactivated.
- Deactivation:
- Allow the belt to retract as far as the last 100 mm (approx.).
- Restraint function must be deactivated at the latest when the last 100 mm are reached. The belt then re-assumes its normal function.
Belt-fastened Sensor For Rear 3-Point Belts With Belt Tensioner, Checking
- Switch ignition on.
- Connect vehicle diagnostic, testing and information system VAS 5051 A or vehicle diagnostic and service information system VAS 5052 and select vehicle system "15 - Airbag" on.
- Read measured value block, display group 004.
Belt fully retracted, display on vehicle diagnostic, testing and information system VAS 5051 A or vehicle diagnostic and service information system VAS 5052: - no -
Latch plate engaged in belt buckle and belt pulled out by dimension - L -, display on vehicle diagnostic, testing and information system VAS 5051 A or vehicle diagnostic and service information system VAS 5052: - yes -
- Pull out belt as far as possible. For this purpose, display on vehicle diagnostic, testing and information system VAS 5051 A or vehicle diagnostic and service information system VAS 5052 must remain - yes -.
- Retract belt as far as dimension - L - without releasing latch plate, display on vehicle diagnostic, testing and information system VAS 5051 A or vehicle diagnostic and service information system VAS 5052 must remain - yes -.
- Release latch plate and slowly retract belt; at the latest when the belt has retracted as far as the last 100 mm, display must switch from - yes - to - no -.
Belt fully retracted, display on vehicle diagnostic, testing and information system VAS 5051 A or vehicle diagnostic and service information system VAS 5052: - no -
- Dimension - L - is 300 mm for left and right belt.