In the summer of 1931 the prototypes were ready for trials. Citroën had received orders for six tractor prototypes: three fully tracked vehicles and three of the half-track type. The first prototype to be ready, not at all resembling the Carden-Loyd carrier, was in the form of a very small half-track fitted with a Kégresse track and manned by only a driver protected by an armoured hood with vision slits, sitting on the left side of the vehicle, with the engine to his right. Only the nose of the vehicle was armoured. It was presented to the "Commission de Vincennes" on 24 July 1931 and tested till 29 July. The commission noted that the cooling system failed and that there was no possibility to decouple the trailer from inside the driver's cabin. On 31 July the other two half-tracks were delivered together with the first two trailers. The matériel was rejected as being too vulnerable. Citroën discontinued the development of the fully tracked vehicles but rebuilt one of the half-tracks prototypes into the prototype of the larger AMR Citroën Kégresse P 28 half-track, fifty of which would be built.