[TJ-Rock]

Apologies, I'm not articulating correctly. Forget about VCM for a second. Remember all of the discussions about how coasting in neutral used more gas than by letting off the gas and keeping the car in gear? From there it was explained that when you let off the gas (when moving) the injectors turn off and the engagement of the drivetrain keeps the pistons moving, not combustion. The injectors only turn on again right before the car stops to enable an idle. So now back to VCM. When VCM is engaged, the front bank of cylinders by the firewall continue to go up and down with no fuel being injected into the cylinder. What is the difference to the cylinder itself bewteen this and coasting (for all cylinders)? The way I see it, nothing. But this would have been the case with the last gen Pilot (with all its VCM issues) as well so my point is there's more going on that's engineering related and way above my paygrade. It's just like carbon and DI. I don't think the DI 2.4's which have been around now since 2013 have carbon issues so once again there some slick engineering going on.

I have never heard of that before, I'll have to hunt down that conversation and look into it.

 

[14v6]

I have never heard of that before, I'll have to hunt down that conversation and look into it.

I was like you, how could that be true but they set me straight years ago, I think it was on the Accord forum. Someone will chime in with explaining it better.

Does Fuel Injection shut off during coasting?

Either during coasting/engine braking, and if it does shut off, how long till it does? Owners manual seems to not have anything on this

www.driveaccord.net

 

[speedlever]

I think part of the problem assessing the longevity impact of VCM could be that many people don't keep a vehicle long enough for the issues to show themselves. I suspect that only those who keep vehicles for the long haul have concerns in this area.

 

[Cochise111]

I'm no engineer and it's way above my pay grade but when the car is moving and I take my foot off the gas don't all injectors stop fuel delivery thus eliminating combustion in the cylinder and the subsequent chain of events that you describe VCM or not? I'll trust Honda on this one and I am very critical of Honda.

Do your injectors stop firing when your car is idling? Without getting technical, there is a good deal of difference when you take your foot off of the gas to coast and your cylinders freewheeling with no combustion at higher RPMs for extended periods. The injectors may cease for a couple of milliseconds, but they are hardly interrupted. The coils probably continue to fire.

 

[wjfyfe]

The oil bypassing the rings was the culprit for engine damage.

OK, oil bypassing the rings is damaging the cylinders, I am still listening?

Bill

 

[bongus]

Just pulled my recently installed VCMuzzler II out. I had it on for a couple of days (less than 100 miles total) and on the 3rd day, I received a P219A error code. I removed the device and the error code was still there. I removed the device around 11:30 AM and later that evening when things cooled off, the error code disappeared. This morning, still no error code. The only thing I can attribute the code to is my installation of the VCMuzzler II.

 

[PeeVeeH]

Just now installed an S-VCM on my 2017 RL. The more I drove the more I hated the VCM that Honda designed. The rumbling noise. The vibration. So after researching on ROC Forum, I decided on the S-VCM. It took a while to get (it comes from Canada), and PayPal screwed up and used my old address to ship to in another state. It finally showed up but in the meanwhile, the S-VCM guy shipped me another unit, and told me to go ahead and keep the first if it shows up. Can't beat that. Installation was a bit of a PITA but only because I have large hands that had to go into a small space. Once installed it acted just as advertised. Temperature gauge now reads a bit lower than before, and VOILA! - no more VCM! So far I can recommend the S-VCM. My RL is once again a pleasure to drive.

S-VCM Controller - Disable VCM / deactivate VCM and stop ECO in Honda Acura

Deactivate Honda VCM in 3.5L V6 SOHC engines. The S-VCM Controller is an automobile grade, high precision tool that can reliably disable VCM 100% of the time, and would safely bypass in case the engine overheats. It does not use a fixed resistor or manually adjusted potentiometer, and is a much...

www.svcmcontroller.com

or, on eBay:

S-VCM Controller - a better alternative to VCM Muzzler, VCMtuner VCMuzzler Honda | eBay

Especially when you are driving in frequent stop-and-go traffic, VCM turns on and off more frequently than when driving freely on the highway. But the busy stop-and-go traffic is where resistor tools cannot keep up.

www.ebay.com

 

[Solo]

I think the only way I'd defeat this system is to have the ECU ( or whatever they're calling it today) re-written. It doesn't make sense to me having the ECU calculating fuel with the input of 165 * all the time.
On a "long" cruise the update turns the VCM off temporarily in an attempt to mitigate problems caused by some of the cylinders not working. Is that correct?

 

[t321sg]

Thank you for that objective post. With researching about Honda's VCM myself, it appears that Honda has refined the system to a point where it is no longer the "trouble maker" it used to be in the past, where bypassing it today no longer has the benefits it used to. As long as the VCM does not create any problems in our Ridgeline, we will be leaving the system to work as designed. In other words, we are not going to fix something that apparently is no longer broken.

Bill

In that research, did you determine what year Honda refined the system so its not a problem? Please share so I can quit worrying myself for vehicles of year ____ and forward.

 

[Cbayman]

No VCM on G1 RLs. All G2 RLs have the updated version of 6-3 VCM.

 

[t321sg]

Does the "eco" light still illuminate on the dash when the engine control module kicks the VCM on? In older Honda cars it did that, but I think Honda did away with the light indicator in newer vehicles so you don't know when VCM has activated.

 

[Cbayman]

There’s no ECO light on the 2G RL to indicate VCM operation. The green “halo” in the instrument cluster indicates more efficient operation but does not indicate the VCM state. There are after market devices available that plug into the OBDII port to dynamically read PCM data including VCM. The device I have is the Scangauge II. The SGII can be programmed to monitor a variety of parameters including, VCM, ATF temperature, ECT, etc. SGII is just one of many products available on the market. Search for “monitor VCM“ on the forum to see what others have done to monitor VCM.

 

[zroger73]

I think the only way I'd defeat this system is to have the ECU ( or whatever they're calling it today) re-written. It doesn't make sense to me having the ECU calculating fuel with the input of 165 * all the time.
On a "long" cruise the update turns the VCM off temporarily in an attempt to mitigate problems caused by some of the cylinders not working. Is that correct?

Yes - even under conditions that allow the engine to run in 3-cylinder mode, it will periodically revert to 6-cylinder mode.

 

[lbjgh]

After more than 18 months of S-VCM bliss I am a believer. My truck averages 10L/100kms in normal driving with smooth predictable acceleration using the S-VCM. I've noticed no issues what so ever.

 

[t321sg]

I wonder if there is a way for an automotive technician to program the PCM or ECU or whatever controls VCM, to deactivate it so it never comes on?

 

[zroger73]

I wonder if there is a way for an automotive technician to program the PCM or ECU or whatever controls VCM, to deactivate it so it never comes on?

Simple answer: No.

That would require reading, reverse-engineering, modifying, and writing the firmware. The middle two steps can be expensive and time-consuming. There has to be a big enough market for a company to justify the investment required to do this. Then, there are legal issues to consider since such a modification could be emissions tampering. I'm surprised there hasn't been a crack-down on VCM and idle-stop defeat devices yet.

 

[t321sg]

Hmmm..Its quite common for any mechanic shop to plug into GMs version of VCM and just deactivate it.

 

[zroger73]

That ability simply doesn't exist for Honda - at least not commercially. Perhaps it's because there are a lot more GMs than Hondas. Perhaps it's because Hondas are harder to reverse-engineer.

Automakers, including GM, have been moving toward encrypted ECUs that effectively eliminate aftermarket modifications. Some of GM's newer ECUs have taken years to crack and their newer models that have either Global A or Global B architecture have yet to be cracked.

 

[FerioEH]

That ability simply doesn't exist for Honda - at least not commercially. Perhaps it's because there are a lot more GMs than Hondas. Perhaps it's because Hondas are harder to reverse-engineer.

Automakers, including GM, have been moving toward encrypted ECUs that effectively eliminate aftermarket modifications. Some of GM's newer ECUs have taken years to crack and their newer models that have either Global A or Global B architecture have yet to be cracked.

I'm pretty sure Hondata would be able to crack it, since they've already done so on the newest civics. Like you said though, such a limited market.

 

[Gary_G]

FWIW to anybody, I have run two different S-VCM units on a 2018 RTL-E for roughly 35,000 miles, and a 2020 RTL-E for just over 10,000 miles now. I have had ZERO problems out of them, and if somebody runs into me and totals my truck today, I will replace both RTL-E and S-VCM with another as quickly as possible. I never personally experienced any of the issues attributed to VCM, but I feel better knowing that my engine is always 'firing on all cylinders' (which is such an ingrained synonym for 'working properly' that I almost feel compelled to add, 'It is right and just.').