Service Update Bulletin - Certain 2020 model year Chevrolet Silverado and GMC Sierra vehicles equipped with a 2.7L Engine (RPO ENL), Engine Control Disable Start/Stop (RPO L3B), and a 3.5? Driver?s Information Center Display (RPO UDC), may have a condition where the start/stop disabling function does not work. Dealers will reprogram the engine control module (ECM) with an updated calibration.
