Cadillac ATS shuddering intermittently at speeds between 40-80 km on Cadillac ATS

Some Cadillac ATS owners report experiencing intermittent shuddering at speeds between 40-80 km/h, which may be linked to transmission issues. This shudder is often described as similar to driving over rumble strips or rough pavement and can occur during light throttle acceleration when the transmission is not actively shifting gears. The problem has been noted in both Drive and M7 MY15-16 & L7 MY17 modes, and diagnosing TCC shudder requires specific driving conditions on a smooth road with the transmission sump temperature between 50°C (122°F) and 70°C (158°F). A technical bulletin suggests flushing and draining the transmission fluids to alleviate shudder during light throttle acceleration at steady speeds. Proper diagnosis is essential, as the shudder may not always stem from the torque converter clutch but could also be due to other factors like fish bite or surge. Additionally, some owners experience shudder when coasting at low speeds before applying aggressive throttle. It is recommended that affected owners have their transmission system inspected by a qualified mechanic to effectively address any underlying issues.