Technically Speaking
- Author: Wayne Colonna
- Subject Matter: VCM technology
- Issue: Shuddering at highway cruises
VCMs can be a big headache, but there’s an easy remedy
The number of vehicles containing VCM exceeds 4 million to date, as far back as 2005 – Odyssey, Pilot, Ridgeline and Accord – and Acura MDX/RDX/TLX that have an I-VTEC engine. This problem affects many more vehicle owners than you could imagine.
VCM technology Honda/Acura developed for their 3.5L was designed to save fuel. When driving conditions are right, the I-VTEC system goes from 6 cylinders down to 4 and then 3. An electronically controlled active control engine mount (ACM) system (liquid filled mounts) is activated to provide a smoother, quieter ride. Inside the cabin of the vehicle, there is also an active noise cancellation (ANC) system to assist in the quieter ride experience during variable displacement activation.
As quiet as the drive may be, this technology has turned into big headache for both the manufacturer and the vehicle owner. This system is known to have the potential for misfires, high oil consumption fouling the plugs, repeated failure of the motor mounts and damage to the torque converter. In fact, the 2015 ATSG seminar covered a scenario where VCM activation can be misinterpreted as a torque converter shutter.
A good friend of mine, Keith Burki, owns a late model Acura (Figure 1). He described this VCM feature as being so annoying he would find alternate routes rather than cruising down the highway. After poking around on the internet, he discovered the VCMTUNER. He installed it and now highway cruising is a pleasure, and interestingly enough, he doesn’t see that much of a fuel economy loss as he originally expected.
The company who designed the VCMTUNER learned that VCM operation becomes active at approximately 167° F. A pacifying temperature device (Figure 2) was invented that can be easily installed onto the ECT1 sensor in the engine compartment (figures 3, 4 and 5). It has a 10-position selector to accommodate a wide variance in seasonal temperatures from which one can dial in the optimum temperature setting. A zero selection will allow the VCM to operate if so desired. As easy as it is to install, it is likewise to remove. This may be necessary should the vehicle need to go back to Honda for servicing. Much more can be learned about this nice little gadget by going to https://www.vcmtuner.com/.
The company recently received their E.O. D-809 by the State of California. This will enable the company to provide two separate versions on the analog product, CARB and non-CARB. There will also be a digital version coming out that will require no adjustment at all. The non-carb version will work with all thermostats available. The CARB version works with factory Honda OEM thermostats up to 80°C. The digital version will be for sale in mid to late August.
Honda torque converter failure can be the result of many different factors. Superior Transmissions has a terrific kit for fixing many of those issues inside the transmission. This VCMTUNER, which sells for $79.95, can be another benefit to make available to customers, adding further torque converter protection – Especially if they too are annoyed with the vehicle shuddering at highway cruises when the ECO light comes on.
