The invention relates to a method for processing at least one motor variable (I_a, U_m) of a DC motor (2) of an actuating device (1) for a motor vehicle, said DC motor being supplied by an on-board system DC voltage (U_B), in which the armature current (I_a) and the motor voltage (U_m) of the DC motor (2) are detected and the actuating position of an actuating element (3) is determined from the time profile of the armature current (I_a) by counting the current ripple (R_n) contained therein. During an initial phase (10), the armature current (I_a) which rises over time (t) is replicated by a function which is determined from pairs of values (U_m1,2, I_{a 1,2}) for the motor voltage (U_m1,2) and the armature current (I_a1,2) which are detected in a time interval (Δt_1,2). From this, a current value (I_x) of the armature current (I_a) which is expected at a later point in time (t₃) is extrapolated, wherein, in the event of a discrepancy (ΔI_ax) between the armature current (I_a) detected at this later point in time (t₃) and the extrapolated armature current (I_x), a ripple count for detecting the current ripple (R_n), in particular the first current ripple (R₁) produced during runup of the DC motor (2), is started.