HOW IT WORKS

The Background: The Honda VCM Problem

Owners of Honda vehicles equipped with 3.5L V6 engines have suffered through far too many trips to the dealership due to engine vibration issues caused by Variable Cylinder Management (VCM) operation.

In 2014, a major lawsuit (known as the "Honda Misfire Settlement") was won against Honda for VCM modes causing excessive oil consumption. As a result, Honda provided owners of 2008-2015 vehicles with an extended powertrain warranty to cover repeated spark plug failures, excessive piston ring wear, and premature engine mount failures.

Early Attempts to Fix the Issue

• Oil Pressure Switch Disconnect: Early on, the only option was to disconnect a secondary oil pressure switch on the engine. While users on forums like Odyclub.com reported this fixed their oil consumption, it permanently triggered a Check Engine Light (CEL), which could void vehicle warranties.
• The 167°F Discovery: In 2014, a user on the Piloteers forum ('Tmuchacho') discovered that the VCM/ECO mode would not engage until the Engine Coolant Temperature (ECT) sensor registered above 167°F.
• Static Resistors (VCMUZZLER II): This led to inline resistor wire harnesses. However, a single resistor value didn't work across all climates. Products like the VCMUZZLER II required users to buy multiple plug-in resistors and manually swap them out as the seasons changed to keep VCM disabled. Depending on the resistor used, the dash temperature gauge could read +/- 20 degrees off from normal.

The Original Solution: VCMTUNER 1.0

To solve the seasonal swapping problem, we created the original VCMTUNER. It utilizes a 10-position selector switch containing a wide range of resistor values. This allows users to "dial in" the optimal value for their climate, showing only a very minimal variance on the dashboard temperature gauge.

VCM can easily be re-enabled simply by turning the dial to position '0', without removing the product from the engine. For dealer visits, it can be entirely removed in minutes. To accommodate vehicles without a battery box near the ECT1 sensor, we revised the VCMTUNER to utilize a compact, tunable plug on a factory-style harness for easy, fine adjustments.

Real-World Results

After building the prototypes and testing them on our own vehicles, the results were night and day. Engine vibration was minimized, and our vehicle stopped burning a quart of oil every 2,500 miles.

Furthermore, passing power on the freeway substantially improved without any hesitation—making the vehicle feel like it was in a "Sport Mode." Now that the VCM problem is completely resolved, we love our Honda Odyssey Touring again. My wife enjoys driving it, and we plan to keep it for the long haul.

Product Evolution Gallery

---

Patent Information

The VCMTUNER technology is fully protected by the USPTO. Patent No. 10,240,541 (Granted in 2019, originally filed Jan 2017 as US 62/444,812 A).

This patent covers all analog and digital potentiometer/rheostat implementations in disabling VCM as a method and system. It also covers the original prototype selector switch with different resistor values, and the optional OEM-style dash switch to enable/disable VCM for use with various analog and digital implementations.

---

Changelog & Hardware Revisions

We continuously look for ways to improve our product to ensure it remains the most robust solution in the industry.