Chevrolet and GMC will temporarily stop producing 5.3L engines with Active Fuel Management and Dynamic Fuel Management in the face of semi-conductor shortages worldwide.

In a memo sent to dealers this morning, General Motors outlined a significant change in the 2021 5.3L L82/L84 engines that feature AFM and DFM. Due to a worldwide shortage of semi-conductors, the company has decided to remove these fuel-saving features from the 5.3L engines until further notice.

The change will go into effect this week. 5.3L engines with AFM will be built without the feature starting today, March 15th. 5.3L engines with DFM will be built without the feature on March 29th.  All pickups built with either 5.3L engine after those dates will not have the fuel-saving features. Pickups produced without AFM or DFM will have a new RPO code, YK9 along with a disclaimer “Not Equipped With Active Fuel Management” or “Not Equipped with Dynamic Fuel Management”. These models will also feature a $50 MSRP credit.

Silverado and Sierra built without AFM/DFM will also receive revised fuel economy estimates. It’s unclear at this time what the new fuel economy of these models might be. Dealers have until tomorrow, March 16th, 2021 to enter orders for production that can include AFM and DFM.

Specific models of Silverado and Sierra affected are listed below. They include pretty much every model of Sierra and Silverado produced today.

Active Fuel Management, also known as “displacement on demand” is a fuel-saving technology that can turn off fuel delivery to a portion of an engine during light load. In the case of the Silverado and Sierra, it can turn the 5.3L V8 into a 2.65L four-cylinder engine when the right circumstances are met.

Dynamic Fuel Management is similar to AFM, but instead of being a set number of cylinders that “turn off” like AFM, the engine computer can “skip” fuel and spark of any combustion chamber, no matter which cylinder is up for firing. In theory, a DFM enabled engine can run on only 1 cylinder or all 8 and any number in between.

The memo released today indicates that this change in the inclusion of AFM/DFM on 5.3L engines will run at least until the end of the 2021 model year. However, with no change in the supply of semiconductors worldwide, this engine change may run into the 2022 model year, GM-Trucks.com speculates.

While some end users may not be happy about these features being removed, a clear sub-set of Silverado and Sierra buyers who do not like AFM/DFM will have a chance to purchase a 5.3L engine without this technology. To those users, this is an extremely rare opportunity that may prompt new truck purchases that would not have happened otherwise.