The passenger compartment of the C5 Aircross remained stable in the frontal offset test. Dummy readings indicated good protection of the knee and femurs of the driver and dummy. Citroën showed that a similar level of protection would be provided to occupants of different sizes and to those sitting in different positions. Readings in the tibia indicated weak protection of the lower leg for the driver but all other body regions were protected well or adequately. In the full-width, rigid barrier test, protection of the driver was good or adequate for all critical body areas. For the rear passenger dummy, head deceleration indicated marginal protection. In the side barrier impact, protection of all critical parts of the body was good and the car scored maximum points. In the more severe side pole test, rib compressions indicated marginal protection for the chest. Tests on the front seats and head restraints demonstrated good protection against whiplash injuries in the event of a rear-end collision. A geometric assessment of the rear seats also indicated good whiplash protection. The autonomous emergency braking (AEB) system performed well in tests of its functionality at the low speeds, typical of city driving, at which many whiplash injuries occur.

In the frontal offset test, protection was good or adequate for both the 6 and 10 year dummies. In the side barrier test, protection was good for all critical body areas. The front passenger airbag can be disabled to allow a rearward-facing passenger to be used in that seating position. Clear information is provided to the driver regarding the status of the airbag and the system was rewarded. All of the restraint types for which the C5 Aircross is designed could be properly installed and accommodated in the car.

The protection provided to the head of a struck pedestrian was predominantly good or adequate on the bonnet surface but was poor along the base of the windscreen and on the stiff windscreen pillars. Protection of pedestrians' legs and of the pelvis was good at all test locations and maximum points were scored. As standard, the C5 Aircross has a camera-only AEB system which can detect and respond to pedestrians. The camera + radar system included with the optional safety pack can also detect cyclists. In pedestrian tests, the system performed marginally, with some collisions avoided and some mitigated. In cyclist tests, the system performance was adequate.

The C5 Aircross has a seatbelt reminder system as standard for the front and rear seats. A camera-based speed assistance system is also standard. Local speed limits are identified and the information is provided to the driver, who can set the speed limiter appropriately. A lane support system helps to prevent inadvertent drifting out of lane and can also assist in some more critical situations. The camera + radar AEB system which is part of the optional safety pack demonstrated adequate performance when tested at highway speeds, an improvement on the marginal performance shown by the standard camera-only system.