Variable Cylinder Management (VCM) is

Honda is a Japanese public multinational conglomerate manufacturer of automobiles, motorcycles, and power equipment, headquartered in Minato, Tokyo, Japan. Honda has been the world's largest motorcycle manufacturer since 1959, reaching a product ...

's term for its

variable displacement Variable displacement is an automobile engine technology that allows the engine displacement to change, usually by deactivating cylinders, for improved fuel economy. The technology is primarily used in large, multi-cylinder engines. Many automobil ...

technology, which saves fuel by using the

i-VTEC VTEC (Variable Valve Timing & Lift Electronic Control) is a system developed by Honda to improve the volumetric efficiency of a four-stroke internal combustion engine, resulting in higher performance at high RPM, and lower fuel consumption at low ...

system to disable one bank of

cylinder A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infin ...

s during specific

driving Driving is the controlled operation and movement of a vehicle, including cars, motorcycles, trucks, buses, and bicycles. Permission to drive on public highways is granted based on a set of conditions being met and drivers are required to fol ...

conditions—for example,

highway A highway is any public or private road or other public way on land. It is used for major roads, but also includes other public roads and public tracks. In some areas of the United States, it is used as an equivalent term to controlled-access ...

driving. The second version of VCM (VCM-2) took this a step further, allowing the engine to go from 6 cylinders, down to 4, and further down to 3 as the computer sees fit. The most recent version of VCM (VCM-3) reverted to the previous 3- and 6-cylinder operation. Unlike the

pushrod A valvetrain or valve train is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine. The intake valves control the flow of air/fuel mixture (or air alone for direct-injected engines) ...

systems used by

DaimlerChrysler The Mercedes-Benz Group AG (previously named Daimler-Benz, DaimlerChrysler and Daimler) is a German multinational automotive corporation headquartered in Stuttgart, Baden-Württemberg, Germany. It is one of the world's leading car manufacture ...

Multi-Displacement System Chrysler's Multi-Displacement System (MDS) is an automobile engine variable displacement technology. It debuted in 2006 on the 5.7 L modern Hemi V8. Like Mercedes-Benz's Active Cylinder Control, General Motors' Active Fuel Management, and Ho ...

and

General Motors The General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. It is the largest automaker in the United States and ...

Active Fuel Management Active Fuel Management (formerly known as displacement on demand (DoD)) is a trademarked name for the automobile variable displacement technology from General Motors. It allows a V6 or V8 engine to "turn off" half of the cylinders under light-lo ...

, Honda's VCM uses

overhead cam An overhead camshaft (OHC) engine is a piston engine where the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion cha ...

s. A

solenoid upright=1.20, An illustration of a solenoid upright=1.20, Magnetic field created by a seven-loop solenoid (cross-sectional view) described using field lines A solenoid () is a type of electromagnet formed by a helix, helical coil of wire whose ...

unlocks the cam followers on one bank from their respective rockers, so the cam follower floats freely while the valve springs keep the valves closed. The system operates through controlling the flow of hydraulic engine oil pressure to locking mechanisms in the cam followers. The engine's

drive by wire Drive by wire, DbW, by-wire, steer-by-wire, fly-by-wire or x-by-wire technology in the automotive or aviation industry is the use of electrical or electro-mechanical systems for performing vehicle functions traditionally achieved by mechanical link ...

throttle allows the engine management computer to smooth out the engine's power delivery, making the system nearly imperceptible on some vehicles. When the VCM system disables cylinders, an "ECO" indicator lights on the dashboard, Active Noise Cancellation (ANC) pumps an opposite-phase sound through the audio speakers to reduce cabin noise, and Active Control Engine Mount (ACM) systems reduce vibration. The VCM hydraulic circuit control is defaulted open, meaning that the engine has to build up enough oil pressure on initial startup to disable the rear bank of cylinders. A single solenoid on the rear camshaft is activated to close oil pressure to unlock the cam followers, thereby closing the valves. In theory, the closing of all rear bank valves produces an ‘air spring’ effect. However, the reciprocating effect of the piston with closed valves reportedly produces a vacuum condition where oil can get pulled past the piston rings to flood the cylinder. When VCM disengages, the engine then misfires if needing to clear the cylinder of oil. This unique type of oil consumption has led to premature failure of parts like spark plugs, catalytic converters, engine mounts, pistons/rings, and cylinder walls. Newer versions of VCM have been developed to improve system reliability but consumers continue to log complaints. Owners of vehicles equipped with VCM frequently face vibration problems due to engine motor mount malfunction while ECO mode is enabled. Instead of replacing motor mounts, owners often override the VCM with a bypass mechanism, such as an in-line resistor based temperature override module. This has the effect of the vehicle computer believing that a sufficient engine temperature to enable VCM has not been reached. While this cannot guarantee that VCM will be disabled (e.g. differing climates/load scenarios), it can generally keep VCM from engaging under normal driving conditions.

Vehicles equipped with VCM

* 2003

Honda Inspire The is a mid-size sedan introduced by Honda in 1990 derived from Honda Accord chassis. The first Inspire debuted in 1990 as the Accord Inspire, a sister nameplate to the Honda Vigor, but sold at different retail channels in Japan, known as ''Ho ...

* 2004+ Honda Elysion V6 * 2005–2007

Honda Accord Hybrid The , also known as the in Japan and China for certain generations, is a series of cars manufactured by Honda is a Japanese public multinational conglomerate manufacturer of automobiles, motorcycles, and power equipment, headquartered ...

('' JNA1'') * 2005-10

Honda Odyssey Honda Odyssey can refer to three motor vehicles manufactured by Honda: * Honda Odyssey (ATV), an all-terrain vehicle (1977—1989) * Honda Odyssey (minivan), a brand of two different Honda minivan models for different markets ** Honda Odyssey (inte ...

(USDM) - EX-L and Touring Models only ('' J35A7'') - 2005-2007 models are equipped with VCM-1 (3- and 6-cylinder operation) - 2008-2010 models are equipped with VCM-2 (3-, 4-, and 6-cylinder operation). * 2011+

(USDM) - 2011-2017 models are equipped with VCM-2 (3-, 4-, and 6-cylinder operation) - 2018+ models are equipped with VCM-3 (3- and 6-cylinder operation). * 2006–2008

Honda Pilot The Honda Pilot is a mid-size crossover SUV with three-row seating manufactured by Honda since 2002. Primarily aimed at the North American market, the Pilot is the largest SUV produced by Honda. Pilots are currently manufactured in Lincoln, Al ...

2WD Models only ('' J35Z1'') - VCM-1 (3- and 6-cylinder operation) * 2008–2017

Honda Accord The , also known as the in Japan and China for certain generations, is a series of cars manufactured by Honda since 1976, best known for its four-door sedan variant, which has been one of the best-selling cars in the United States since 1989. ...

V6 (except EX-L V6 6MT Coupe) - 2008-2012 models are equipped with VCM-2 (3-, 4-, and 6-cylinder operation) - 2013-2017 models are equipped with VCM-3 (3- and 6-cylinder operation). * 2009+

(all models) - 2009-2015 models are equipped with VCM-2 (3-, 4-, and 6-cylinder operation) - 2016+ models are equipped with VCM-3 (3- and 6-cylinder operation). * 2010-2014 Acura TSX (V6) * 2013

Acura RDX The Acura RDX is a compact luxury crossover SUV produced by Acura, a luxury vehicle division of Honda, as the second crossover SUV offering from the brand after the mid-size MDX. Initially sharing its platform with the Honda Civic and CR-V, wi ...

V6 * 2013

Acura RLX The Acura RLX is a mid-size flagship luxury car manufactured by Honda and sold under their Acura division, released in 2013, succeeding the Acura RL, RL. The RLX was discontinued in 2020. Background and development The Acura Legend was a very suc ...

- VCM-3 (3- and 6-cylinder operation) * 2014

Acura MDX The Acura MDX is a mid-size luxury crossover SUV with three-row seating produced by the Japanese automaker Honda under its luxury Acura division since 2000. The alphanumeric moniker stands for "Multi-Dimensional" luxury. It has ranked as the seco ...

- VCM-3 (3- and 6-cylinder operation) * 2015

Sport Hybrid - VCM-3 (3- and 6-cylinder operation) * 2016-2020

Acura TLX The Acura TLX is a four-door entry-level luxury sedan sold by Acura, a luxury division of Honda, since 2014. It is the successor to both the TL and TSX models. As of 2021, the discontinuation of the RLX leaves the TLX as the flagship sedan in ...

V6 * 2017

Honda Ridgeline The Honda Ridgeline is a midsize pickup truck manufactured by Honda. The Ridgeline is the only pickup truck currently produced by Honda. The Ridgeline is built using a unibody frame, a transverse-mounted engine, and is only offered in a crew–cab ...

References

{{Reflist

External links

CanadianDriver article

Honda Worldwide , Technology Picture Book , VCM
Engine fuel system technology Honda cs:VCM de:Zylinderabschaltung fr:VCM ms:Pengurusan Silinder Boleh Laras ja:VCM

Vehicles equipped with VCM

See also

References

External links