The passenger compartment remained stable in the frontal impact. Dummy readings indicated good protection for the knees and femurs of both the driver and front passenger dummies. Citroën were able to show that a similar level of protection would be offered to occupants of different sizes and to those sat in different seating positions. The DS4 scored maximum points for the protection it provided in the side barrier test. In the more severe side pole impact, protection of the chest and abdomen areas was adequate and that of the head and pelvis was good. The seat and head restraint provided marginal protection against whiplash injuries in a rear-end collision.
Based on dummy readings in the frontal and side impact tests, maximum points were scored by the DS4 for protection of the 3 year child. The front passenger airbag can be disabled to allow a rearward-facing child restraint to be used in that seating position. The switch is clearly marked and unambiguous information is provided to the driver regarding the status of the airbag, and the system was rewarded. Permanent labels warn clearly of the dangers of using a rearward facing restraint in this seating position without first disabling the airbag.
The bumper provided good protection to pedestrians' legs. However, the front edge of the bonnet was marginal or poor. In most areas likely to be struck by the head of a child, the bonnet offered good protection. However, in those areas likely to be struck by an adult's head, protection was rated as poor in all areas tested, and no points were scored for this part of the assessment.
Electronic stability control is standard on the DS4 and met Euro NCAP's requirements. There is a seatbelt reminder system for the driver, front passenger and rear seats. A driver-set speed limitation device is also standard equipment on the DS4.