CITROEN DS4 Owner's Handbook Manual page 233

The function displays the following types of message:
Parking possible
Parking difficult
Parking not advised
The function deselects itself automatically:
- when you engage reverse gear,
- when you switch off the ignition,
- if measuring is not requested,
- within five minutes of selection of the
function,
- if the vehicle speed exceeds the
threshold of 45 mph (approx. 70 km/h) for
one minute.
If the lateral distance between your vehicle and
the parking space is too large, the system may
not be able to measure the space.
The system remains available after each
measurement and can therefore measure
several spaces in succession.
In poor or wintry weather, ensure that the
sensors are free of dirt, ice or snow.
The parking space sensor system deactivates
the front parking sensors when measuring
forwards.
If there is a fault, have the system
checked by a CITROËN dealer or a
qualified workshop.
231
Driving