The cause of the condition may be a reduction in the number of cylinders firing during deceleration, which can lead to structure-borne noise/vibration/harshness complaints.
This bulletin applies to 2021 Chevy Silverado 1500 vehicles equipped with a 5.3L engine and 10L80 automatic transmission. Customers may comment when coasting to a stop between 13-15 mph, there is a shudder-type sensation that can also feel like driving over rumble strips.
The cause of the condition may be a reduction in the number of cylinders firing during deceleration, which can lead to structure-borne noise/vibration/harshness complaints.
If these conditions are found and verified, do not replace any parts. Reprogram the ECM with the latest calibration and perform Crankshaft Position Variation Learn procedure as outlined in the service manual.
Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety ofspecialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.
