18316 - Customer Satisfaction Program. Certain 2018 model year Chevrolet Express and GMC Savana vehicles, equipped with 4 wheel disc brakes, may have a condition where when the right rear wheel is driven over rumble strips a vibration in the rear axle causes the right rear wheel speed sensor (WSS) to produce an erratic signal. The ABS, Stabilitrak and Traction Control lights will illuminate on the Instrument Panel and set ABS Diagnostic Trouble Code C0050 0F. The Service Stabilitrak and Service Traction Control message may also be shown on the Driver Information Center. ABS, Stabilitrak, and Traction Control functionality would not be available until the next ignition cycle. Dealers will reprogram the electronic brake control module (EBCM) with an updated calibration.