Mercedes-Benz C-Class (W205) 2015 - 2021 Owners Manual: Activating/deactivating the seat belt's child special seat belt retractor

When enabled, the special seat belt retractor ensures that the seat belts of the front passenger seat and rear seats do not slacken once the child restraint system is secured.

The seat belts on the following seats are equipped with a special seat belt retractor:

• Front passenger seat
• Rear seats

• To install a child restraint system: when installing a child restraint system, always observe the manufacturer's installation and operating instructions as well as the information in this Operator's Manual.
• Pull the seat belt smoothly from the seat belt outlet.
• Engage the seat belt tongue in the seat belt buckle.
• To activate the special seat belt retractor: pull the seat belt out fully and let the inertia reel retract it again.

  When the special seat belt retractor is activated, you should hear a ratcheting sound.

• Push the child restraint system down until the seat belt sits tightly.
• To deactivate the special seat belt retractor: press the release button of the seat belt buckle.
• Hold the seat belt tongue and guide back to the seat belt outlet.