This recall affects certain vehicles equipped Occupant Classification System (OCS) control units manufactured by Continental Automotive Systems. A varistor in the OCS control unit may have been manufactured out of specification. Under certain conditions, this could interupt the signal between the OCS and the air bag control unit (ACU), causing the passenger air bag to be suppressed in an accident. If the air bag does not deploy when needed in a crash, the risk of injury is increased. Dealers will test the signal between the OCS and ACU with a special tool to verify proper function. The seat cushion containing the OCS hardware will be replaced as necessary. The recall began November 4, 2008.