Automatic seat belt checklist (540i 2021-2022, 540i xDrive 2021-2022, M550i xDrive 2018-2019, M550i xDrive 2020-2022)
| Has the automatic seat belt with the lower strap been replaced after an accident, e.g. in a frontal and/or oblique collision in which the impact absorber/deformation elements were permanently deformed? (only while safety belt was fastened) | No | Replace complete automatic safety belt The following must also be checked and, if necessary, exchanged: Seatbelt mounts on the vehicle body Seatbelt mounts on the seat Seat rails. |
| Yes | ||
| Does safety belt lock when pulled out suddenly? | No | Replace automatic safety belt (upper seat belt). |
| Yes | ||
| Is the belt slack from removed by the electronic motor retractor (EMA)? | No | Replace automatic safety belt (upper seat belt). |
| Yes | ||
| Can the seat belt strap be pulled out without clamping? | No | Electrically motorized reel is loose - tighten reel. If fault persists: Return spring broken - replace automatic safety belt (upper seat belt). |
| Yes | ||
| Does the strap on the front seat belts retract automatically? Does the strap on the rear seat belts retract automatically, a small remaining loop is acceptable if this remaining loop is completely rolled up when the belt strap is being fed back. |
No | Electrically motorized reel is loose - tighten reel. Too much friction in the automatic seat belt guides (upper seat belt). Return spring broken - replace automatic safety belt (upper seat belt). |
| Yes | ||
| Does the automatic roller make rolling and squeaking noises when it is put on or taken off? | Yes | Too much friction in the automatic seat belt guides (upper seat belt). Electrically motorized reel is loose - tighten reel. Return spring broken - replace automatic safety belt (upper seat belt). |
| No |
| Is the plastic sheathing on the belt tongue in the area of the belt strap opening free of damage? | No | Replace complete automatic safety belt |
| Yes | ||
| Is the fully extended seat belt strap free from Pinches, Combustion marks, Tears and cuts, Creasing and Unraveling? |
No | Replace complete automatic safety belt |
| Yes | ||
| When the seat belt is on, is the belt tongue pushed out of the lock with spring pressure by pressing the "red button"? | No | Replace complete automatic safety belt |
| Yes | ||
| Does fastened seat belt lock during emergency braking on a dry roadway at double walking speed? | No | Replace complete automatic safety belt |
| Yes | ||
| Is fully pulled-out seat belt strap free of serious dirt and other marks? | No | If dirt and marks cannot be removed with commercially available mild detergent, the automatic safety belt (upper seat belt) must be replaced. |
| Yes | ||
| For the seat-integrated seat belt, is the front tongue of the reclining seat fitting or the seat rail free of deformation? | No | Replace both damaged parts and complete automatic-reel safety belt. The following must also be checked and, if necessary, exchanged: Seatbelt mounts on the vehicle body Seatbelt mounts on the seat rails. |
| Yes | ||
| The automatic seat belt is OK! |