Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Trunk central locking drive (trunk lock)
The central locking drive for the trunk is equipped with a motor for unlocking.
The central locking drive contains two microswitches which are actuated by the locking pawl. If the locking pawl is in the pre-locking position, the status of the microswitch changes from a high signal to a low signal. The electronics in the automatic soft-close drive register the status and activate the drive. As soon as the locking pawl engages in the main locking position, the drive stops.
The second microswitch is used to switch on the luggage compartment lighting. The change in the status of the microswitch which occurs when the trunk is opened or closed is also used to monitor the trunk for the purposes of the anti-theft alarm system.
The automatic soft-close drive is connected to the trunk lock with a Bowden cable. This has the benefit that the drive can be fitted regardless of the available installation space. The drive is connected to terminal 30B. The fuse is located in the rear power distribution box. An electronics module is integrated into the automatic soft-close drive which is used to monitor its proper functioning.
Closing the trunk places the rotary striker in the trunk lock in the pre-locking position. To this end, a microswitch is located in the trunk lock which changes status when the lock is actuated.
The electronics module in the automatic soft-close drive evaluates this change in status and triggers the drive to switch on. The automatic soft-close drive is actuated until the rotary striker is located in the main locking position. Once this has occurred, the microswitch changes status again and the drive is switched off.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.