Pre-CE evolution of the WD progenitor covering the TP-AGB phase up to the onset of the CE evolution, which takes place at the last helium shell flash shown. We show the evolution of the orbital period (P_orb), the hydrogen and helium burning luminosities (L), the wind mass loss rate (Ṁ_wind), and the radius, as a function of the mass of the hydrogen-free core. Although several thermal pulses occurred before the WD progenitor filled its Roche lobe, leading to substantial core mass growth, the TP-AGB star is not yet highly evolved, as evidenced by its radius and wind mass loss rate. This causes the mass transfer to be dynamically unstable which generates CE evolution.