18189 - Customer Satisfaction Program. Certain 2018 model year Chevrolet Express and GMC Savana vehicles, may have a condition in which the chassis harness is misrouted between the body and the frame. Systems such as the side blind zone alert or park assist system may become inoperable if the wires were to become damaged. If this damage were to occur, the driver would be notified via a Driver Information Center (DIC) message stating ?Service Side Detection? or ?Service Park Assist?. Reroute the chassis harness to inside of the frame.