2015 Buick LaCrosse Owner Manual - Page 231

9-46 Driving and Operating Other Vehicle Lane Changes Do Not Use ACC on Hills and When Towing a Trailer When following a vehicle and entering a curve, ACC may not detect the vehicle ahead and accelerate to the set speed. When this happens, the vehicle ahead symbol will not appear. ACC will not detect a vehicle ahead until it is completely in the lane. The brakes may need to be manually applied. ACC may detect a vehicle that is not in your lane and apply the brakes. ACC may occasionally provide an alert and/or braking that is considered unnecessary. It could respond to vehicles in different lanes, signs, guardrails, and other stationary objects when entering or exiting a curve. This is normal operation. The vehicle does not need service. Do not use ACC when driving on steep hills or when towing a trailer. ACC will not detect a vehicle in the lane while driving on steep hills. The driver will often need to take over acceleration and braking on steep hills, especially when towing a trailer. If the brakes are applied, the ACC disengages.