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VCM disable - a new and better way

583290 Views 1481 Replies 384 Participants Last post by  verbatim
relatively new to this forum, but not new to reading the threads here. I have read almost all the posts on the VCM vibration issue and for those that aren't familiar with it, please do a search and do some reading as I don't plan to recap everything.

My opinions and experience are this: I don't like VCM at all. I am one of those that are experiencing vibrations and that's why I came to this forum in the first place. I have always been of the opinion that equipment is meant to be run, and when it's not, bad things happen. Cylinders in an engine are meant to be firing at all times and when they're not, you get oil bypassing, plug fouling, misfiring, vibration, and all the bad things that each of these conditions leads to. Adding active engine mounts and noise cancelling technology is just adding more crap to try and hide a bad condition. It is an initiative to help save 1 mpg and is more of a gimmick to satisfy EPA regulations etc. It's bad for engines as can be seen by all the complaints here and with every automaker that tries this.

My original intent was to try everything people here do to get rid of the vibration, pcm updates, engine mounts, spark plugs, etc etc... then I realized I needed to focus on disabling this B.S. system instead.

I tried disconnecting the rear bank oil pressure switch as is recommended by many. It did indeed disable VCM, however it was accompanied by the CEL indications, DTC's. As well, I live in a cold, snowy, icy climate and when I did this, after a short time of driving, the VTM-4 light came on in the dash and I noticed immediately that I had much less traction. The vehicle became a 2wd vehicle. At every start from a stop on a slippery surface, the front end slid to the side and there was not the usual amount of traction. It was painfully obvious that VTM-4 was also disabled. this was unacceptable to me. I need 4wd and I couldn't live with the CEL codes. If you like a 2WD vehicle and warnings all over your dash, by all means use this method. If you want something better, read on.

As most of you know, VCM doesn't engage until the engine is up to operating temperature. According to my OBD II device, it kicks in at around 167 degrees. This is where I decided to focus my attention. After doing some research on the ECT sensor, I went out and bought a 1K potentiometer. I drove my pilot until it was at operating temp and then I stopped and pulled ECT 1 sensor wire. I put the pot inline with the sensor, then started the engine and using the OBD II reader, I dialed the pot until the engine temp read 165 degrees. I went for a test drive and there were no CEL lights and the VCM never engaged. It was heavenly to drive the vehicle with VTM working, no CEL codes, and no VCM. It was how this vehicle should drive.

Now know what some of you are thinking. What if the engine overheats? I'll never know. Well, my plan is this. I'm going to install a switch and an aftermarket digital coolant gauge with audible alarm. So, what I'll do is run the vehicle up to operating temperature in the normal position so that if the engine needs the ECT reading to adjust anything, it can. then \I'll flick the switch and VCM will be off and the potentiometer will be sending a signal that the engine is at 165F to the PCM. that's less than ten degrees below operating temp and shouldn't cause any problems. I certainly didn't see any when I was driving. I also will have the aftermarket sensor monitoring engine temp, and giving an alarm if it overheats.

The only thing I'm unsure of at this point is whether the radiator fans will come on in hot weather as usual. I believe they will because I'm pretty sure they use ECT 2 as the input for this. I'll find out I guess.

I plan on making it look like a very professional installation, using one of the blank spots next to the DTS switch to install my switch. Not sure exactly where the aftermarket gauge will go yet. I've ordered the OEM female connector to make a harness so that I don't have to cut any wires and I can put it back to original with no evidence. The male half of the connector is going to be a bit more difficult as it isn't sold individually and so I'm going to try to hack apart an IAT sensor to make one.

For those that are interested in this, I will post updates of my progress with pictures. I just thought I'd share what I found so far.

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This sounds great, but if the engine is thinking it's not up to operating temperature, won't it also make the engine run richer than needed, and we all know a rich mixture will also cause all kinds of fouling of plugs, gunk buildup, etc.
Also, having to monitor your coolant temp on the side is basically a wash with having to check your CEL constantly for real fault codes with the other method.
Seems like both methods have their pluses and minuses.

I wish someone can just figure out a firmware hack or Honda would release an official disabled VCM firmware (even if only to Honda techs at dealers!).
Honda will never issue a PCM fix that disables VCM so everyone can stop hoping. That would violate the emissions and EPA rating it currently has and so they would face fines and lawsuits. I Have contacted range technologies and they are interested in trying. They asked me if I had anything I could share for info. They are listening at least
I know they will never do it for the general public. I was just hoping they would add an option like this to the diagnostic tools in the Honda HDS tool so that maybe at least a Honda tech can disable it for testing purposes (and accidentally forget it was left disabled!). ;)
If the Pilot is a cluster-hump to this degree because of VCM.... and they refuse to do anything about it then I will have to scratch the 2016 off my list.... which is truly a shame. Was hoping to ditch my 2014 Highlander, which has vibration issues of it's own for a stylish new Pilot.... but the first several threads and 'stickys' in this forum have scared the devil out of me.

I cannot imagine 'tinkering' around with a brand new vehicle to circumvent a poorly implemented - (shall we call it what it is: DESIGN FLAW) which may come back to haunt you if something happens to the vehicle and they discover the engine has been jury-rigged.

Darn it...... I was really exited to see the new Pilot...... there are fewer viable options now..... 2015 Murano can only tow 1,500 lbs..... Highlander has it's own issues with vibrations and poorly implemented less concerning items, Ford Explorer has tiny seat bottoms, Hyundai Santa Fe LWB feels 'cheap' and isn't all that quiet and smooth on the road, Kia Sorento is too small......GM's can't get out of their own way - underpowered, Mazda CX9 is a gas hog and outdated...... this sort of leaves me with two options: Dodge Durango (which is being phased out in 2017) and the upcoming new Ford Edge... released this spring.
I am as much against having a VCM engine as any other Honda VCM owner with issues, but I would hold off on ruling it out until we see the 2016 Pilot. That will surely be a new generation of engine and even with VCM, it seems like the newer ones like the ones in the new Acura RLX and TLX are more problem free (or maybe they just aren't old enough yet to show the problems). I'm a loyal Honda lover, so I am seriously hoping they have ironed out the issues with VCM since it doesn't appear they are abandoning it.
Ok, another quick update. I've zeroed in on the optimal resistance value. I removed the potentiometer and replaced it with a permanent resistor. Still no issues to report other than VCM free operation. I've also discovered that if I make the switch first thing in the morning when the engine is completely cold, there are no CEL warnings returned at all, so this can be both installed and removed without any warnings appearing on the dash.

I was also able to clear the previous "stored" code by disconnecting the battery. It never stored a "permanent" code when I checked with my diagnostic tool and It appears that if you install this cold, you'll never get a code anyway.

So now, I'm just waiting on the male connectors. The guy from the China supplier got back to me and said give him a week because of the Chinese New Year, so hopefully he gets back to me soon with a quote. I'm likely going to be out a bunch of money on this deal because I'm going to have to order 100 of everything due to their minimum quantities. I'm skeptical that there will be enough interest here to sell enough to make my money back, but that doesn't matter to me, I'm just doing this to help people out.

For those that are interested, I'll keep you posted. Once I have all the parts and I make one up, I'll put a posting on EBAY for it.
I think if this really works as well as what you describe and if it works on other Honda models with VCM, you won't have much problem selling 100 of them. Between just the Odyssey and Pilot forums there are plenty of people who want to do away with VCM. The only question is, will it work reliably on different Hondas and in different climates (i.e. Phoenix vs Miami vs Alaska vs Canadian areas).
O7 pilot ex with vcm. Will it work? I noticed your pilots were 08 to 12. I'm happy to beta test it. And I'm in Florida. Temps are 80s now soon to be 90s and 100 by june.
Do you have a 2wd Pilot? I think 4WD Pilots all didn't have VCM back in 07.
Just passing along my update on the VCMuzzler. Install was straight forward. Once installed the ride was great. Especially in cruise mode, except for this morning. On my way into work about 5 min. into the drive the CEL came on and said "Check Emission System". That caught me off guard cause I've been using the VCMuzzler for the last month and no issues. Now this morning we had abnormally low temps than the last few weeks. It was 35 degrees so this would have been the first time it would have run in those temps. So I unistalled the VCMuzzler and took it to Advance Auto to have it diagnosed. And sure enough it was the coolant temp out of range "too cold". So with that being said has anybody run into this scenario. I've ordered a OBDII tool to clear the code and will be installing the VCMuzzler. Hopefully it was just a fluke and everything will work out fine in the future. If it does happen again maybe an adjustment needs made to the resistor value. I know that the climate changes and there are many variables. Otherwise the VCMuzzler worked great and my gas mileage was not affected during the time it's been installed.
That seems strange that you would get a CEL for coolant temp too cold. I mean there are WAY WAY colder climates than 35 degrees and you would think they would experience way colder coolant temps. What about those Alaskan winters when it's like -40 degrees out and they need block heaters just to keep the engine starting properly? What was the exact OBDII code that you got?
It has mostly to do with mileage, emissions, and CAFE ratings. You can't certify a car with VCM and then provide an easy way for drivers to defeat it such that the tested cars don't represent how the cars are actually driven.

- Mark
I wonder how hard it would be for someone with access to the PCM software at Honda corporate to make a custom personal version without VCM activating. I'm surprised that with everyone being so connected these days that some insider hasn't chimed in and offered something like this "under the radar". They could make a nice little chunk of change on the side AND more importantly, make lots of Honda and Acura owners much happier!!!
Well, technically right now they cant pursue legal action but that may change. Right now, many other aftermarket mod guys make a variety of products intended to override the PCM programming. Some modules are made to increase performance at the expense of fuel economy. Many many people add "chips" to their vehicles for this purpose and companies sell these all the time with no worry about being sued. Fact is, it's your vehicle and you can do anything you want to it. You own it, not Honda. What Honda and other automakers will do is void your warranty if they see aftermarket equipment installed in your vehicle that they feel gives them the right to do so, whether it's truly justified or not.

What is interesting is that there is a movement started by the big automakers in the courts right now to make it illegal for anyone but the dealer to work on, or modify, your vehicle. Interestingly, they are attempting to claim that your vehicle's PCM programming is protected by copyright laws and as such any attempt to work on the vehicle without being authorized is an infringement of copyright laws and hence illegal. This is being criticized, obviously, as an obvious attempt to monopolize the auto repair industry and push out independent facilities. I highly doubt the big automakers will be successful in this bid.

While it is possible to crack the PCM programming, it is no simple task. You need a lot of knowledge of automotive electronics and programming to begin with and then you need the equipment and time to reverse analyze it to determine all of the algorithms. It is a very big task, and while not impossible, you would need to have a specific goal in mind when doing this i.e. to want to offer a fuel mapping device to override the PCM and increase performance.

In the case of disabling VCM, it's not as easy as just cracking the code to come up with a method to disable VCM without affecting anything else. That has to be actually programmed already in the PCM software in order for that to be possible. In the example of the GM ACM system, GM actually did provide an input from their diagnostic tool that will disable ACM for testing purposes. Range technologies capitalized on this and came up with their device that plugs into the OBD port and sends the signal to disable ACM. Honda has no such programming. The evidence of this is that in any TSB where they want the technician to disable VCM and do a test drive to see if it is the culprit, they don't say "use the diagnostic tool to disable VCM", they instruct them to pull the connector from the pressure switch, which we know works, but gives all sorts of codes and disables some other systems. Therefore I would not expect anyone to come up with this kind of solution for Honda. coming up with a whole new PCM that replaces the OEM one, but does not allow VCM to engage is a huge undertaking and not many people would trust that they emulated the rest of the PCM programming exactly. Not only that, but when you pull the OEM PCM, you remove all the OEM data that's being stored there for when they do diagnostics. Even if you swapped it back for those times that you take it in for service, there would likely be a big gap in the collected data that would tip the dealer off about your modifications. This is how many of the guys that "chip" their vehicles get caught.
I agree completely with everything you say here and I know it will be next to impossible to get a true VCM disable, but my thinking was this:

While it is a MAJOR undertaking to reverse-engineer the PCM to modify it and do it correctly, it should be a simple task for an inside Honda engineer that works on the PCM software. It should be no more than a simple change in the PCM code somewhere as long as you know where it is.

I would be really surprised if no one who works on the PCM software at Honda has heard about VCM issues or even read the tons of threads like this on the topic. Seems like they would be able to produce a PCM version without VCM very easily. I know it would be against Honda policy, etc... but I'm just saying I wonder if someone has done this if only for themselves.
I'm not shipping out any more gen 1. I'm working on a gen 2, which will have the ability to swap out resistors for a higher value when needed. I'll keep everyone posted here and will reply to any PM's that were sent to inform people on when the new one will be ready.
Will you have an upgrade path for those with your Gen1?
Wow... looks fantastic. Very professional appearance. If I have a gen 1 VCMuzzler and I want to upgrade to the Gen II, but I can't bear to part with my existing one while shipping and waiting for it to come back, can I just buy a Gen II and when it gets here, I send you back the Gen I and when you receive it, just issue me a 50% credit or whatever the difference in cost is?
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