What is Honda cylinder deactivation?
VCM (Variable Cylinder Management) is fuel-saving technology that automatically deactivates 1/3 or 1/2 of the cylinders, according to the driving conditions. This saves fuel and lowers emissions.
How does the cylinder deactivation system work in a Honda?
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 and 7 on the left bank, and cylinders 4 and 6 on the right bank, switching to a V4 mode.
What happens when you deactivate 3 cylinders in accord?
When idling those 3 cylinders, the system also alters ignition timing and turns the transmission’s torque converter lock-up on and off, to suppress jolting during the transition between 6- and 3-cylinder operation. Later, Accord and Pilot models could also get VCM.
How to diagnose a cylinder deactivation code?
Because of this, diagnosing any cylinder deactivation codes should begin by making sure that the engine is filled to the proper level with the appropriate oil and that engine oil pressure is within specifications. If there is doubt about actual engine oil pressure; a manual oil pressure test is in order.
How are cylinders deactivated in a Mercedes Benz?
Some of the troublesome V8-6-4 engines were later converted into conventional V-8s. Full-size Mercedes-Benz models sold in Europe in 1999 had something new: an Active Cylinder Control system that deactivated half the cylinders in the V-8 or V-12 engine. Mercedes’ system used twin arms to actuate each valve, controlled by a computer.
What kind of cylinder deactivation system does Honda Accord use?
New VCM cylinder deactivation system is integrated with i-VTEC valvetrain and allows the ’08 Accord’s 3.5L SOHC V-6 to operate in 3-, 4- and 6-cyl. modes.
What does VCM mean on a Honda Accord?
Variable Cylinder Management ( VCM) is Honda ‘s term for its variable displacement technology, which saves fuel by using the i-VTEC system to disable one bank of cylinders during specific driving conditions—for example, highway driving. The 2008–12 Accords took this a step further,…
What happens to a cylinder when it is deactivated?
In addition to the valves being closed on the deactivated cylinders, the cylinder deactivation system also disables fuel flow to the affected cylinders. There is usually no noticeable loss of power or torque when the cylinder deactivation system becomes operational.
What’s the 3 cyl mode on a Honda Accord?
For maximum gains at low engine loads, VCM reverts to 3-cyl. mode and shuts down the transverse-mounted engine’s entire rear bank of cylinders. Six-cylinder operation is used only at startup and for accelerating.