What Chevy engines have AFM?

The Chevy engines that use AFM are primarily the 5.3L V8 and the 6.2L V8 from GM’s small‑block family.

Active Fuel Management (AFM), also known as Displacement on Demand, deactivates half of the cylinders under light-load conditions to save fuel. GM offered AFM on several generations of the 5.3L and 6.2L V8 engines in Silverado/Sierra pickups, Tahoe/Yukon, Suburban, and related models across multiple years. In the late 2010s, GM began shifting toward Dynamic Fuel Management (DFM), which expands and refines cylinder deactivation for better efficiency and responsiveness on newer engines.

Which Chevy engines have AFM?

The following GM engines have AFM in certain years and configurations.

• 5.3L V8 (Vortec 5300) — widely equipped with AFM in many trucks and SUVs during its AFM era.


• 6.2L V8 (Vortec 6200) — also offered with AFM in many full-size trucks and SUVs throughout its AFM period.

AFM presence varies by model year, trim, and market. Always verify with the VIN, engine code, or build sheet to confirm whether AFM was installed or if the system has been replaced by Dynamic Fuel Management in newer models.

In short, the primary AFM-equipped Chevy engines are the 5.3L V8 and the 6.2L V8. Newer GM applications have shifted toward Dynamic Fuel Management (DFM), while older AFM setups remain in service on many late‑2000s to mid‑2010s vehicles. When shopping used Chevy trucks or SUVs, check the engine code or the window sticker to confirm AFM/DFM status.

How AFM works and what to know

AFM uses a system of variable-lift lifters to deactivate four cylinders in the V8 during lighter loads, effectively running the engine as a 4-cylinder in certain conditions to improve highway fuel economy. The system engages and disengages automatically based on driving conditions. While AFM helped boost efficiency in many applications, some owners reported lifter and cam-related noise or reliability concerns, particularly on early implementations. GM later introduced Dynamic Fuel Management (DFM) as a more flexible successor to AFM, expanding which cylinders can be deactivated and smoothing transitions between modes.

AFM today and what it means for buyers

As GM moved into the late 2010s and beyond, many engines originally built with AFM were updated to Dynamic Fuel Management (DFM) or redesigned for the new system. If you’re buying a used Chevy, you’ll want to confirm whether the vehicle has AFM, DFM, or neither, and whether any AFM-related service or delete has been performed.

Tips for prospective buyers

Before purchasing, consider these factors to understand AFM/DFM status and potential maintenance concerns.

• Check the engine code and window sticker for AFM/DFM designation and whether the vehicle carries any AFM-delete modifications.


• Review service history for AFM-related campaigns, lifter/cam work, or repairs.


• Test-drive to listen for AFM-related transitions and verify smooth operation when the engine switches between 8 cylinders and 4 or more with DFM.

Conclusion: If you want the most current fuel-management approach, look for vehicles with Dynamic Fuel Management; otherwise, verify the AFM configuration and be aware of its maintenance implications on older AFM-equipped engines.

Summary

AFM has historically appeared on Chevy’s 5.3L and 6.2L V8 engines, aiding fuel economy by deactivating cylinders under light load. GM has since transitioned many newer engines to Dynamic Fuel Management, which broadens how cylinder deactivation works. For buyers or owners, the key is to confirm whether AFM or DFM is installed in a given vehicle and to review maintenance history related to the system.

How to tell if 5.3 has DOD?

You can tell if a 5.3L engine has DOD/AFM by checking the valley cover for channels, looking for the DIC message "Engine Running in V4 Mode" on the dashboard, or using the 8th digit of the VIN, which should be a '3' for DOD.
 
This video shows how to identify if your engine has VVT or AFM/DOD: 57sDinoco BlueYouTube · Oct 21, 2020
Method 1: Check the valley cover 

• The valley cover is located under the intake manifold.
• If it has channels or a ribbed design on top, the engine has DOD. 
• If the cover is smooth, the engine does not have DOD. 

Method 2: Check the dashboard (Driver Information Center - DIC) 

• The DIC display, located below the tachometer, will show "Engine Running in V4 Mode" or a similar message when the system is engaged. 

Method 3: Check the VIN

• Find the 8th digit of the vehicle's Vehicle Identification Number (VIN).
• If the 8th digit is a '3', the engine has DOD. 

Method 4: Inspect the engine

• Look for a label on the engine cover that says "AFM" or "Active Fuel Management".
• The engine's valve covers may also have a unique design or markings due to the AFM integration. 

Which GM engines have an AFM?

GM used the Active Fuel Management technology on a range of engines including with the GM Small Block Gen IV engine family, first-generation GM EcoTec3 engine family, second-generation GM High-Feature V6 DOHC engine family, and first-generation High-Feature V8 DOHC engine family.

Can Chevy AFM be turned off?

An AFM Disabler is an electronic device that plugs into the OBD-II port, under the dashboard. It prevents the computer from switching over to 4 cylinder mode. It's a simple and effective way to turn off the AFM system. It will also improve the sound of the exhaust.

Do all 5.3 have cylinder deactivation?

No, not all 5.3L engines have cylinder deactivation, although most have had it since around 2007. For example, some 2007-2013 models were an exception, and more recently, certain 2021-2022 models were built without it due to chip shortages, a feature often noted on the window sticker as having a credit for the missing system. The engine hardware may still be present, but the active system was temporarily disabled. 
Key points about cylinder deactivation in 5.3L engines

• Early models: The first models to feature cylinder deactivation were in the mid-2000s, and it became more widespread in 2007. However, some 2007 "Classic" models were not equipped with it. 
• Specific model years: Between 2007 and 2013, cylinder deactivation was a standard feature in the 5.3L, but not on other engines like the 6.2L or 4.8L. 
• Recent exceptions: Some 2021-2022 models were produced without the deactivation feature due to the global chip shortage. Owners who have these trucks may have a credit on their window sticker. 
• Newer models: Starting around 2019, GM introduced a more advanced Dynamic Fuel Management (DFM) system that can deactivate up to seven cylinders dynamically. However, the system can still be affected by engine oil clogs or other issues and some 2021-2022 models were built without it. 
• 2026 model year: The 2026 Chevy Silverado is expected to have a 5.3L V8 engine without cylinder deactivation.