Does BMW require matching when replacing the airbag clock spring?
2 Answers
BMW requires matching when replacing the airbag clock spring. Function of the airbag clock spring: When a car collision occurs, the airbag system is highly effective in protecting the safety of the driver and passengers. Current airbag systems are typically single airbag systems in the steering wheel or dual airbag systems. When a vehicle equipped with dual airbags and a seatbelt pre-tensioner system is involved in a collision, regardless of the speed, both the airbag and seatbelt pre-tensioner will activate simultaneously. As a result, the airbag may be wasted during low-speed collisions, leading to a significant increase in maintenance costs. Working principle of the airbag clock spring: When a car is hit by an oncoming vehicle, the airbag control system detects that the impact force (deceleration) exceeds the set value. The airbag computer immediately activates the electric detonator circuit in the inflator component to ignite the ignition medium in the electric detonation pipeline. The flame ignites the ignition powder and gas generant, producing a large amount of gas. The airbag inflates within 0.03 seconds, causing the airbag to expand rapidly, breaking through the decorative cover on the steering wheel and providing a sense of security to the driver and passengers. This action cushions the heads and chests of the occupants, absorbing the impact on the driver and passengers, and then releases the air from the airbag.
I've driven a BMW for several years and have also replaced the clock spring. This component mainly connects the horn and buttons on the steering wheel, as well as the circuit module for the airbag. Usually, no special matching or programming is required after replacement because it's not a smart electronic device but rather a physical wiring harness part. However, after installation, the airbag system might show a fault code because the airbag area was disturbed, triggering the protection mechanism. I recommend using a diagnostic tool to clear the fault code or initialize the system to ensure the airbag light doesn't stay on and the functions work properly. Otherwise, ignoring it might potentially affect the airbag's response time. It's safest to have a reliable repair shop check it to avoid any regrets in case of an accident.