Steering assistance is part of Pilot Assist and can only be used when Pilot Assist is active.
If steering assistance is unavailable for some reason, such as deteriorated lane markings, you won't be able to activate it. However, if steering assistance is enabled, it will automatically activate when the required conditions are met.
Note
Temporary loss of steering assistance
The availability of active steering assistance depends on the conditions you are experiencing. For example, if you encounter a stretch of road with worn out markings, the vehicle may temporarily turn steering assistance off. If this happens you are notified with vibrations in the steering wheel.
on the steering wheel.Steering assistance is either enabled or disabled.
If enabled, steering assistance activates automatically when the required conditions are met.
If disabled, Pilot Assist will remain active but mainly provide speed- and distance-keeping.