How does Chevy cylinder deactivation work?

How Chevy Cylinder Deactivation Works
Chevy’s cylinder deactivation, also known as Active Fuel Management (AFM), is a technology that improves fuel economy by shutting down half of the engine’s cylinders during light driving conditions. Here’s how it works:
1. Valve Control: Cylinder deactivation is achieved by controlling the intake and exhaust valves of the selected cylinders. Special valve lifters with spring-loaded locking pins are used to connect the internal pin housing of the lifter to the outer housing.
2. Solenoid Control: One VLOM (Valve Lifter Oil Manifold) solenoid controls both the intake and exhaust valves for each deactivating cylinder. There are separate oil passages for the hydraulic lash-adjusting feature of the lifter and for controlling the locking pins used for cylinder deactivation.
3. Timing: Cylinder deactivation is timed so that the cylinder is on an intake event. During an intake event, the intake cam lobe pushes the valve lifter upwards to open the intake valve against the force of the valve spring.
4. Pumping Loss Reduction: When some cylinders are deactivated, no air goes in or out of them, resulting in reduced pumping loss. The engine automatically compensates for the missing cylinders, creating less of an intake-exhaust pressure difference. This reduces pumping loss in the active cylinders, making them work more effectively and improving overall engine efficiency.
5. Computer Control: The cylinder deactivation system is controlled by the engine’s main control unit, which takes into account various factors and variables to determine when to activate or deactivate cylinders. This includes factors such as engine load, speed, and driving conditions. The system uses sophisticated algorithms and computer code to make these decisions.
It’s worth noting that while cylinder deactivation can improve fuel economy, some drivers may choose to disable it for various reasons, such as wanting consistent V8 power or concerns about potential issues with AFM lifters. However, it’s important to consult with a professional or refer to the manufacturer’s guidelines before attempting to disable or modify the cylinder deactivation system.
I hope this explanation helps! Let me know if you have any further questions.

What year 5.3 has cylinder deactivation?

General Motors ever popular 5.3L active fuel management was used in majority of trucks and SUV’s from 2007-2014. This was one of GM’s first designs utilizing cylinder deactivation and active fuel management.

Is cylinder deactivation bad for your engine?

If the engine is equipped with a cylinder deactivation system, we face a new potential failure mode. Increasing the valvespring pressure or just increasing the amount of lifter movement at speed may be enough to overwhelm the oil pressure keeping the lifter in full operation.

What happens during cylinder deactivation?

When a cylinder is deactivated, solenoid-controlled oil pressure releases a locking pin between the two rocker arms. While one arm still follows the camshaft, the unlocked arm remains motionless and doesn’t move the valve. With computer control, fast cylinder deactivation and reactivation occur almost instantly.

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.

How bad is Chevy cylinder deactivation?

When functioning correctly, cylinder deactivation should not cause long-term engine damage. However, problems left unaddressed, such as misfires or sensor issues, can potentially lead to engine damage over time.

What is the truth about cylinder deactivation?

In diesel engines, cylinder deactivation is used for the purpose of exhaust heating. By deactiving cylinders at low loads, the remaining active cylinders work harder and produce more heat, which gets the aftertreatment system hotter quicker and reduces emissions.

Does AFM cause engine damage?

However, the design is not without its flaws. The system designed to shut off half the cylinders using special lifters, also causes irreparable damage to the camshaft and lifter due to very common failures.

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.

How does Chevy 5.3 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.

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.