Infantry squads are pinned/disrupted by suppressive attacks only. Vehicles are not affected by suppressive attacks.
Normal attacks that cause light damage against light vehicles (trucks, half-tracks) cause -1 MV and -1 Armor. Also, they must immediately end their movement in the hex they are damaged. Normal attacks that cause heavy damage against light vehicles destroy result in No Movement, and 1/2 Firepower.
Normal attacks that cause light damage against a heavy vehicle (tank) cause -1 MV and -1 Armor, but may continue movement as normal. Heavy damage affects heavy vehicles the same as light vehicles. Hope this helps. See page 28 in the side bar for the exact info.