Which GM engines have cylinder deactivation?
Cylinder deactivation is a technology used in many modern engines to improve fuel efficiency by shutting down some of the engine's cylinders during light-load conditions. General Motors (GM) has been a pioneer in implementing this feature across a variety of its engines. In this article, we’ll explore which GM engines are equipped with cylinder deactivation and how this technology works.
What Is Cylinder Deactivation?
Cylinder deactivation, also known as Active Fuel Management (AFM) or Dynamic Fuel Management (DFM) in GM vehicles, is a system that temporarily disables certain cylinders in the engine when full power is not needed. This reduces fuel consumption and emissions without compromising performance when power is required again.
GM Engines with Cylinder Deactivation
GM has incorporated cylinder deactivation technology into several of its engines, particularly in V6 and V8 configurations. Below is a list of GM engines that feature this technology:
- 5.3L EcoTec3 V8 (L83, L84): Found in vehicles like the Chevrolet Silverado and GMC Sierra, this engine uses AFM or DFM depending on the model year.
- 6.2L EcoTec3 V8 (L86, L87): Commonly used in larger SUVs and trucks, such as the Chevrolet Tahoe and GMC Yukon, this engine also features AFM or DFM.
- 4.3L EcoTec3 V6 (LV3): This V6 engine, used in some Chevrolet Silverado and GMC Sierra models, includes AFM technology.
- 3.6L V6 (LGX, LFX): Found in vehicles like the Chevrolet Camaro and Cadillac XT5, this engine may include cylinder deactivation depending on the specific model and trim.
How Does GM's Cylinder Deactivation Work?
GM’s cylinder deactivation systems operate by deactivating the intake and exhaust valves of specific cylinders. This is achieved through advanced valve lifters that can disengage when the system determines that less power is needed. The engine control unit (ECU) monitors driving conditions and seamlessly switches between full-cylinder and reduced-cylinder operation to optimize efficiency.
Benefits of Cylinder Deactivation
There are several advantages to GM’s cylinder deactivation technology:
- Improved Fuel Efficiency: By reducing the number of active cylinders, the engine consumes less fuel during light-load conditions.
- Lower Emissions: Fewer active cylinders mean reduced exhaust emissions, contributing to a cleaner environment.
- Seamless Operation: The transition between active and deactivated cylinders is virtually unnoticeable to the driver, ensuring a smooth driving experience.
Conclusion
GM has successfully integrated cylinder deactivation technology into many of its engines, offering drivers a balance of performance and efficiency. Whether you’re driving a full-size truck or a sporty sedan, this feature helps reduce fuel consumption without sacrificing power when you need it. If you’re considering a GM vehicle or need assistance with maintaining your engine, feel free to reach out to Kevin’s Autos for expert advice and service!
Frequently Asked Questions
Do all 5.3 have cylinder deactivation?
Yes. 5.3 and 6.2, unless your 19-22 5.3 is stated with the window sticker (idk if theres a code) that the 5.3 is to come without DFM. 2500's never have or will come with AFM/DFM.
Why is 2014 the worst year for Silverado?
Of the best and worst years for the Chevy Silverado 1500, the 2014 model year is the worst of the worst. With over 250 problems reported and 19 recalls, this model is reputable for electrical issues, airbags not deploying or failing to inflate, and transmission oil cooler lines prone to failure.
Does GM 6.2 have cylinder deactivation?
DFM in GM engines can shut down any number of cylinders, following 17 different patterns, depending on driving conditions and throttle input. The system helps GM's OHV 6.2L V-8 achieve a 2-mpg (0.9 km/L) gain in real-world fuel efficiency without sacrificing any of the engine's 420 hp and 460 lb. -ft.
What year did GM have cylinder deactivation?
General Motors was the first to modify existing production engines to enable cylinder deactivation, with the introduction of the Cadillac L62 "V8-6-4" in 1981.
Which GM engines do not have an AFM?
The LM2 Duramax 3.0L turbo-diesel, the L8T 6.6L V8, and the LS3 have neither AFM nor the latest version, called DFM (Dynamic Fuel Management). In addition, some 5.3L V8s from 2021 and 2022 don't include either fuel-saving system due to semi-conductor shortages manufacturers were dealing with during that time.
Can you turn off cylinder deactivation?
Unfortunately, optimizing the system requires that we adjust the triggers that make us step from all cylinders to shut-off mode and back again. Looking at popular aftermarket tuning software options, there are several ways to disable the system, based on rpm, VSS, gear, voltage, run time, and more.
How do I know if my 5.3 has Active Fuel Management?
Engine Cover Markings — Many GM engines equipped with AFM will have a label or badge on the engine cover indicating “AFM” or “Active Fuel Management.”
Can GM AFM be turned off?
The engine will have 25 less pounds of compression in those four cylinders which can result in a misfire code. You will need to turn off the AFM system using a computer programmer or custom tuning. It's a little more work, but it's recommended that you plug the pressure relief valve in the oil pan.
What year did the 6.2 get AFM?
The 5.3L engine had it from 2007+, the 2009+ hybrid Escalade, and 2010+ 6.2L engines were equipped with it. It's very possible you could still have a collapsed lifter, but the 2009 6.2L doesn't have AFM. Lifter failure is still seen but just not as often.
What year to avoid AFM?
The AFM system is supposed to disable engine cylinders when you're not using them to help you save gas. Unfortunately, it was faulty, especially in the years between 2010 and 2014, which are definitely some of the Chevy Silverado model years to avoid.
