Honda Lawsuit
An introduction to Honda's Variable Cylinder Management (VCM) technology, the mechanical flaws that lead to engine damage, and the resulting class-action lawsuits.
The Evolution of the VCM Problem
VCM-1 (2005-2007)
The 3.5L V6 VCM-1 engine performs cylinder deactivation on cylinders 1-3. Because only half of the cylinders are utilized during deactivation, misfire and oil consumption issues typically begin to show up at higher mileages (usually above the 100k mile range) as wear accumulates over time.
VCM-2 (2008+)
The updated VCM-2 engine deactivates up to cylinders 1-4. Due to this highly aggressive programming, vehicles began showing excessive oil consumption as early as 10,000 miles. This severe defect ultimately led to the massive Honda Engine Misfire Settlement in 2013/2014.
Why Does VCM Cause Engine Damage?
Many mechanics who rebuild these engines speculate that during cylinder deactivation, the engine vacuum physically starves the shutdown cylinders of adequate lubrication.
Furthermore, spark plugs extracted from these engines show heavy discoloration caused by a mixture of uncombusted fuel and oil. Over time, this mixture causes micro-abrasions on the cylinder walls, leading to a loss of cylinder compression, heavy oil consumption, fouled spark plugs, and eventually throwing misfire codes (e.g., P0301, P0302, P0303, P0304).
The "Timer" Flaw
Some vehicle manufacturers (like Chrysler, who utilize a similar system called MDS) program a strict timer into their engine computers. On early 5.7L MDS engines, deactivation only lasts for a few minutes to ensure the cylinders are quickly re-lubricated, minimizing damage.
Our internal testing of Honda's VCM shows that on a long downhill slope, Honda's cylinder deactivation can stay engaged for intervals up to 10 minutes at a time. From our research into Honda's own patents, they do not specify a maximum time limit for cylinder deactivation to prevent lubrication losses—which is likely the root cause of the lost cylinder compression.
Official Service Bulletins & Lawsuit Documents
Honda's own Technical Service Bulletin (TSB) details their attempt to reduce how often VCM engages during light loads to curb oil consumption. However, the documents openly state that this software update only "may" reduce oil consumption, with no guarantee it resolves the actual physical problem.
Honda TSB A11-033
Honda's official service bulletin regarding VCM software updates.
2013 Lawsuit Notice
The official notice for the class-action engine misfire settlement.
2013 Lawsuit Order by Judge
The judge's official order regarding the Honda VCM litigation.
Video Evidence & Documentation
Excessive Oil Consumption
Documenting 2.25 quarts of oil consumption on a brand new Honda Odyssey.
VCM Vibration Issues
Honda's official explanation of the vibration issues caused by the VCM system.