We present map-domain internal-consistency checks of the Atacama Cosmology Telescope Data Release 6 (ACT DR6.02) using All-Array (AA) temperature maps at 90 and 150 GHz. Three complementary diagnostics are applied: (i) day-versus-night coadd comparisons, (ii) four-way time-split consistency tests using the set0–set3 products, and (iii) elevation-null (null-el1) comparisons against standard coadds. Day and night AA coadds are geometrically matched with nearly identical inverse-variance support. Daytime maps are shallower by factors consistent with the expected sensitivity penalty from atmospheric loading. However, the ivar-normalized day–night residual widths significantly exceed unity. Nighttime split tests confirm the pattern, with setcoadd widths elevated and setset widths elevated, demonstrating that the excess is not unique to the day–night boundary. Null-el1 maps show substantially enhanced weighted variance and enhanced pixel-scale roughness relative to standard coadds, with consistent behavior across PA5, PA5, and the independent array PA4. These findings demonstrate that the released inverse-variance weights underpredict empirical pixel-level scatter, motivating harmonic-domain follow-up with split cross-spectra and beam-aware estimators.