The A2Πi state of 12C16O+ has been reinvestigated using high-resolution, emission spectra obtained via Fourier-transform spectroscopy of the (0, 1), (0, 2), (1, 0) and (1, 1) bands of the Comet–Tail (A2Πi − X2Σ+) system with accuracy of up to 0.005 cm−1. The high temperature (900 K) of the emission discharge inside the hollow-cathode lamp permitted monitoring of high rotational quantum levels in A2Πi(v = 0, 1) up to J = 48.5. All these bands together with the X2Σ+ − X2Σ+(10, 1) and (10, 2) transitions deriving from a complex, spin-orbit, spin-electronic and L-uncoupling A2Π(v = 0) ∼ X2Σ+(v = 10) interaction as well as the B2Σ+ − X2Σ+(6, 10) frequency transitions from our previous study were taken into consideration. In total, 1849 spectral lines were included in the comprehensive deperturbation analysis. This fit leads to a much improved description in terms of deperturbed molecular constants and interaction parameters compared to the previous studies of the same energy region in CO+. Moreover, the ro-vibronic term values of the A2Πi(v = 0) level and its perturber X2Σ+(v = 10) were determined as well as Λ-doubling of A2Πi(v = 0,1), γ-doubling of X2Σ+(v = 10) and percentage 2Π character of these levels were considered in detail.