How does Chevy Active Fuel Management work?

How Chevy Active Fuel Management Works
Chevy Active Fuel Management (AFM) is a technology developed by General Motors (GM) to improve fuel efficiency in their vehicles. AFM, also known as Cylinder Deactivation or Displacement on Demand (DoD), allows a V6 or V8 engine to “turn off” half of its cylinders under light-load conditions, such as when cruising or driving at a steady speed. By deactivating cylinders, the engine consumes less fuel, resulting in improved fuel economy.
Here’s how Chevy Active Fuel Management works:
1. Solenoid System: AFM uses a solenoid system that collapses the valve lifters to reduce pumping losses. This system stops the fuel supply to two or four cylinders, depending on whether it’s a V6 or V8 engine.
2. Valve Lifters: Special valve lifters are required for the cylinders that will be deactivated. These lifters are designed to prevent the deactivated cylinders from operating while the engine is in AFM mode.
3. Lifter Oil Manifold Assembly: A lifter oil manifold assembly is also needed for AFM to function properly. This assembly helps control the oil flow to the lifters and ensures smooth operation of the system.
4. Cylinder Deactivation: In V8 engines, AFM deactivates cylinders number 1, 7, 4, and 6. In V6 engines, it deactivates cylinders 3 and 6. The specific cylinders that are deactivated may vary depending on the engine model.
5. Dynamic Fuel Management (DFM): In newer models, GM has introduced Dynamic Fuel Management, which is an enhanced version of AFM. DFM offers up to 17 different cylinder patterns, allowing the engine to optimize power delivery and efficiency based on load and other inputs.
The primary goal of Chevy Active Fuel Management is to improve fuel economy by reducing fuel consumption during light-load driving conditions. By deactivating cylinders when they are not needed, the engine operates more efficiently and conserves fuel.
It’s important to note that while AFM can improve fuel efficiency, some drivers may prefer to disable or delete the system for various reasons, such as a desire for consistent V8 power or concerns about potential issues with AFM lifters.
Overall, Chevy Active Fuel Management is a technology that helps GM vehicles achieve better fuel economy by intelligently deactivating cylinders when they are not required for optimal performance.
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Why do AFM lifters collapse?

Collapsed or stuck AFM lifters due to oil contamination will result in the same. Contamination/sludge is a major concern, prompting some to re-evaluate mileage service intervals. GM’s Active Fuel Management (AFM) system allows a V8 engine to turn off half of its cylinders for fuel economy purposes.

Does Active Fuel Management really work?

Estimated performance on EPA tests shows a 5.5–7.5% improvement in fuel economy. GM’s Active Fuel Management technology used a solenoid to deactivate the lifters on selected cylinders of a pushrod V-layout engine.

Does AFM actually save fuel?

Range AFM Plus works with your factory installed AFM allowing your vehicle to drive in V4 mode up to 80% of the time, maximizing your fuel and dollar savings. The average driver can save approximately 65 gallons of gas per year or about $250.

Can GM AFM be turned off?

The Range AFM/DFM Disabler allows your V6 or V8 GM vehicle to run in full cylinder mode at all times, preventing the Active and Dynamic Fuel Management systems from dropping cylinders. Our patented technology is the only product that will disable Active or Dynamic Fuel Management without reprogramming the factory ECU.

Why do AFM lifters fail?

We have found that most lifter faults are caused by oil pressure issues, or control issues. The AFM activation and deactivation is controlled by the Valve Lifter Oil Manifold or VLOM.

What is the problem with the Active Fuel Management system?

Common issues include:

• Oil consumption greater than one quart per 1000 miles.
• Combustion chamber deposits resulting in excessive pinging and fuel mileage drop.
• Lifter and/or camshaft failure.
• Engine failure due to ring issues.

What causes AFM lifter failure?

These lifter concerns may be the result of internal locking pin damage, which may occur if the response time of an AFM lifter unlocking event is decreased due to low oil pressure, oil aeration, internal engine sludge, or an internal concern with an AFM lifter, VLOM, plastic lifter guide, lifter bore, and/or cam lobe …

How does the Chevy AFM work?

Active Fuel Management (AFM) was a system GM engineers developed back in 2005 to help improve the fuel mileage from some of their V6 and V8 engine applications. AFM shuts off half of your engines cylinders to operate at a reduced power level to reduce fuel consumption when running in low load and cruise situations.

Will disabling AFM void warranty?

Because no tuning is involved with your vehicle’s computer, this product will not void the factory warranty. Not only does the AFM Disabler keep your vehicle running smoothly, but it will also have you running on all cylinders, all the time.

How do I know if my range AFM disabler is working?

On the latest AFM DISABLER Modules, the four blue lights are basically to indicate the unit is operating. THEY WILL GO OUT WHEN THE VEHICLE IS NOT RUNNING as described below (Power Saving). The lights are as follows: LED #1 – Power is ON and unit is AWAKE and vehicle is ready for commands.