The invention relates to a two-stage solenoid valve for an electropneumatic valve control unit, particularly a pilot control unit of a pressure modulator. Said solenoid valve at least comprises a solenoid system (6) to which a first and second current intensity can be applied as well as a solenoid valve device (8) that is accommodated in the solenoid system (6) and is provided with a primary side(8a) to be connected to a first compressed-air supply and a secondary side (8b) to be connected to a second compressed-air supply. A primary valve (10) encompassing an adjustable primary armature (10a) that is biased by means of a primary armature spring (10c) is provided on the primary side, while a secondary valve (11) encompassing an adjustable secondary armature (11a) which is biased by meansof a secondary armature spring (11c) is provided on the secondary side. The solenoid valve device (8) is embodied as a valve cartridge which is to be inserted from one side. Advantageously, the diameters or a forward zone (18a) and a central zone (18c) of the valve cartridge (8) are smaller than or identical to the diameter of a rear zone of the valve cartridge, ''forward'' being in relation to the direction of insertion.