AFM (Active Fuel Management)
To provide maximum fuel economy under light load driving conditions, the engine control module (ECM) will command the cylinder deactivation system ON to deactivate engine cylinders 1, 7, 6, and 4, switching to a V4 mode.
The engine will operate on 8 cylinders, orV8 mode, during engine starting, engine idling, and medium to heavy throttle applications.
AFM–active fuel management strategy which deactivates the lifters on specific cylinders.
On V8 engines, it deactivates half of the cylinders (1,7,6 and 4) and on V6 engines, it deactivates only 2 of the cylinders (3 and 6).
For LTA and LT2 engines, the deactivation occurs on cylinders 2, 3, 5 and 8.
LOMA–lifter oil manifold assembly is only used on legacy AFM applications
DFM (Dynamic Fuel Management)Dynamic Fuel Management (DFM) is recognized as active fuel management technology with the additional ability to deactivate any combination of cylinder valves for an internal combustion engine.
This technology combines millisecond-accurate torque control with cylinder deactivation to optimize fuel consumption of spark ignited engines.
The control of every cylinder event optimizes engine operation such that peak efficiency is obtained throughout the range of engine operation. DFM extends cylinder deactivation to all cylinders, which allows for a large variety of firing sequences.
DFM can have rotating cylinder deactivation patterns as well as fixed patterns.
For rotating patterns, which cylinders are being deactivated can change with each subsequent engine cycle.
Transitions between firing sequences is done in a continuous fashion, making thetransitions seamless and transparent to the vehicle operator.
DFM–dynamic fuel management which can deactivate the lifter on any cylinder at anytime.
Unlike AFM, this can result any many different types of firing patterns, some of which are fixed patterns (like ¼, ½, ¾) and others which are rotating (like 1/5, 1/3, 2/5,2/3).
This is only available on small block engines (L84 and L87).OCV–oil controlled valve is only used on small block engines.
These provide faster response times than LOMA and are required for DFM (on L84 and L87). OCVs are also used on L82
