Honda Odyssey Forum banner
1 - 20 of 190 Posts

·
Registered
Joined
·
227 Posts
Discussion Starter · #1 ·
Hello there,

First of all, I'd like to say that I'm not an Ody owner, I own a Pilot. I, like many other Pilot owners had problems with VCM causing vibrations when activated particularly during cold weather. Not knowing what VCM was or what it was all about, I took to my computer to learn all about it and decided very quickly that it is flawed technology, leading to grief for many including oil bypassing and excessive consumption, misfire, plug fouling, vibrations issues and potentially long term engine damage. I also found out quickly that there is no good way to disable it without causing CEL codes and disabling of other systems when removing the connector on the oil pressure switch.

Because I believe Honda only created VCM to improve it's fuel efficiency ratings, and meet CAFE regulations and sell more cars, I set out to come up with a better way to disable it. VCM isn't good for an engine. Both Honda and GM have proven that now. Their PCM flashes and component swaps, extended warranties and TSB's all prove that out.

So I believe I've solved this for those that want to disable it. I've come up with a solution that isn't through programming as nobody has figured that out yet, but I've used it for about 2-3 months now and I love it. My Pilot runs like a dream and I love having no VCM activate. the drop in Mileage is minimal. Others urged me to spread the word specifically to the Ody forums because there are many Ody owners that are unsatisfied with this technology also that honda has forced upon us. My searches here have confirmed that to be true.

My solution creates no CEL codes and can be installed in a about a minute and can be reverted to stock in the same amount of time for those times when you want to take it to the dealership.

I've checked with the moderators and they seem to be open to me posting this in the classifieds section, but I just want to make 100% sure before I do. It's been a popular fix so far and I want to help others rid themselves of VCM. Engines aren't meant to drop cylinders, nobody has been able to do it without issues yet. Having said that, I'm not saying that VCM always causes problems. The majority of owners are either not sensitive enough to it's side effects, or their vehicles don't ever experience any issues. However, there are plenty of others that are.

This has all been discussed over and over in many forums so I don't want this to be another divided debate on whether VCM is good or bad, I'm just offering up my solution to those who hate it like I do. I was seriously considering selling my Pilot, but now I love it.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #8 ·
Relax folks I'm not hiding anything. A resistor inline with the ECT1 circuit fools the PCM into thinking the engine hasn't reaches operating temp so VCM never engages. The actual operating temp of the engine is unaffected because it's controlled by the thermostat and the cooling fans. The cooling fans still kick on because ECT2 is unaffected and turns them ok. A/f ratio seems unchanged as this is controlled by other sensors and IAT plays the role for that when it comes to temperature. I've ran it for months now and no indication of running rich or lean, just smooth driving with no annoying dash lights (CEL or ECO).

not everyone is going to agree but my experience and others with this mod has been great so far.

The only downside is that your indicated engine temp is about 15 degrees lower so if in the unlikely event that your engine overheats, it will be fifteen degrees hotter when the warning comes on. However if you note the new normal operating temp as just slightly below what it was and monitor it like you should then you won't have an issue.

I'm doing this mainly to help others out. Take it or leave it, my main goal was to disable it for myself first.

More than happy to answer any and all questions.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #11 ·
Along those same lines, is there a sort of time limit before VCM is enabled after all other conditions are met?
eg. Say all other conditions are met for VCM to be enabled, maybe there's a 60 seconds timer that kicks in before VCM is actually available to be activated?
If that would somehow be the case, I can easily see a circuit which would switch that resistor in for a second or two every 60 seconds. PCM sees normal temps for the bulk of the time, but the VCM never gets enabled due to the time-out.
I haven't been able to detect anything like what you describe. VCM seems to activate instantaneously when the Engine Coolant Temperature as reported by ECT1 reaches 167 degrees. Once it is active, it doesn't stop activating (under the appropriate conditions of course) until the temperature drops back down to about 162-163 degrees. I'm not saying there isn't some sort of time lapse, I just haven't been able to detect one and I'm not sure what the purpose of a time delay would be in the algorithm if all other conditions are properly met.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #12 ·
I'd be interested - if its just a simple resistor, why not try it? I'm hoping the fix is the same on the 4th gen engine
I've consulted the parts finder for various models of Honda and Acura vehicles. PCM's for different models, and even different years of the same model are often different, but I believe the programming for when VCM engages would be the same for all. So for other compatibility, I looked at valve rocker arm assembly to see if the VCM components are the same and I also looked at ECT1. If the components were all the same, I felt that I could group those makes and models together as ones that would benefit from the same fix. What I discovered for the Odyssey is that the 2008-2015 engines all use the same components, so I believe it would work for the 4th Gen engine. It seems that in 2007 and prior engines, the VCM components were slightly different. In the 2005 and 2006 models, they used an older model ECT1 with a different connector type.

Long story short, I believe the harness I have developed will work just fine for 2008-2015 Odyssey. It may work for 2007 if the PCM programming is the same for that model of VCM engine (very likely). It won't work for 2005 and 2006 models because the ECT connectors are a different type. I could make a harness with the older connectors to try on an older engine and it's VCM system, but I don't have a vehicle to test it on.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #13 ·
I think one drawback of that strategy may be the ECU will interpret the lower coolant temperature as a lukewarm engine and consequently enrich the air fuel mixture to the detriment of fuel economy. If it's cold enough to disable VCM, it will probably enrich the mixture. Time will tell. In the interim, I can live with the CEL.
One of the main reasons I pursued this was that when I pulled the pressure switch connector, like many now do, it for some reason disabled other systems in my pilot, the most disturbing of which to me was VTM-4, or the 4WD system. It turned my pilot into a 2WD vehicle and in my climate, that was bad. My traction while driving in the winter was terrible compared to what it was, so I couldn't live with that. While on the odyssey, that's not an issue, seems that for many, when they pull the connector, it also disables the VSA system, which I also would not want to disable. Additionally, running for extended periods with codes recorded in the ECU could give your dealer grounds for voiding your warranty because you did not bring your vehicle in for service when there were CEL codes visible. I'm not saying they would do that, but some dealers will use any excuse to try to void a warranty claim.

As I mentioned in another post, I do not believe the ECU uses coolant temperature to determine much in regards to the A/F ratio. The IAT, MAP and O2 sensors etc. take care of that for the most part. I have not noticed any evidence of running rich. The amount of fuel economy that I've seen dropped is about 1 MPG, which if you look at Honda's numbers for fuel efficiency with and without VCM, appears to be just about exactly what you'd expect to lose.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #16 · (Edited)
I bought a OBD II diagnostics tool that transmits the ECU sensor readings wirelessly to my smartphone. Among everything else, it transmits the ECT1 reading, which I monitored to find the actual temperature that VCM kicks in at. Then, I went online and researched Honda's ECT sensors and how they work. What resistance range is typical for those temperatures and then bought a potentiometer in the range I needed, put it in the circuit and kept playing with the added resistance for a while until I reached what I feel is the right amount by monitoring the new temps with the OBD tool. Took some time and different outside temperatures to come to the final value.

As far as the installation time, that's the beauty of it. It takes literally less than a minute to do in either direction. If you want to revert back to stock, it takes the same amount of time. No cutting into wires, nothing. You unplug the connector from ECT1, take my harness and plug it into the connector you just unpluged. the other end plugs into ECT1. That's it. You might want to take the engine cover off for easier access, but it's not necessary. that would add about another two minutes to the process. I went through the effort to make it completely sealed and uses the OEM connectors that took me a while to find, and the tools necessary to properly make up the terminals and seals within those connectors.

Price? Well, I'm going to take the chance and post it to the classifieds now. I got what I think is approval from the moderator, but I was just really leary about posting due to the very strongly worded warnings in the classified stickies. I've not reached 20 posts yet or been here six months, but I am not here to just peddle my wares, I'm here to try to help people with this, at the urging of others. I plan on staying around here and discussing this and other issues that I feel I can weigh in on as I am a self proclaimed "techie" lol.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #18 ·
I'd sure like to try your fix on my 2006 EX-L. What would it take to test it and more importantly, what could go wrong if it didn't work correctly?
Well, my harness won't work on an '06 because for earlier years, honda used a different ECT sensor connector. It's similar but my harness won't plug in to your connectors.

I haven't tested older models at all. the VCM components are slightly different in your engine than the newer generation VCM. However, I believe Honda would have used the same logic to not engage VCM until the engine is up to operating temperature. I believe they do this because they know full well that deactivating cylinders can cause bad things at times, and doing so when the cylinders are cold and not properly lubricated would be even worse. therefore, I feel the ECU programming would be very similar and so there's a very good chance that it would work for yours as well.

I also think the risk of trying it out is small. The best thing to do would be to buy the OBD tool like I did and monitor engine temp before and after the mod and compare. If you just see a shift of about 15 degrees or so and nothing else seems to be affected, except VCM doesn't engage then you're good to go. If it throws codes, the temperature shift isn't what you'd expect, or you notice anything else that doesn't seem right, then it might not work for you, but it's highly unlikely that this would cause any permanent damage to anything.

I have been asked this before by other owners of older vehicles and so I'm willing to purchase some connectors for your vehicles and make up some harnesses for people to try. It would be good to offer everyone the same opportunity to disable VCM. If you want to help out, locate ECT1, remove the connector and post a close up picture of it for me. I'm pretty sure I know which one it is, but Sumitomo made two slightly different connectors for those older vehicles and I'm not quite sure which it is. I'd have to go to the pick and pull to be sure but if you could post a pic it would save me a trip.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #22 ·
No problem. I wasn't sure so I asked in a PM but didn't get an answer.

In that case the answer to the previous question asked is that it is USD $35.00 plus shipping.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #23 ·
In my pilot it was simple. My pilot like others, experienced vibrations when VCM was active in cold weather. For the pilot they light seems to be tied directly to VCM. As soon as the light comes on you feel the vibrations. Now no light and no vibrations. To be clear, when your engine drops cylinders, the engine starts to vibrate and make noise. The Honda active engine mounts and active noise cancellation through your speakers just masks it so you can't feel it. On the pilot the front propeller shaft would vibrate so you could actually feel it.

Honda came out with TSB for pilots and Acura RDX to fix the problem and it's helped but not been totally eradicated. With the mod there is no more VCM for sure.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #25 ·
On the pilot that's the way it works but It might not be true for all generation pilots. I've heard people say on other models and other gen pilots that the ECO light is independent of VCM but I don't know that first hand. It stops the ECO light for me. Thank god. Never understood why automakers insist on this distraction.

It really is that simple to install.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #33 ·
OK, now this is being really anal, but here is what I take from that explanation:

On your Pilot, there are 2 indications (let's call them "symptoms") that the VCM is active: the ECO light and the vibrations. After the mod, both symptoms were eliminated. No ECO light, no vibrations. From a purely scientific perspective, all we know is that your resistor altered a signal to the computer, causing it to do something different which resulted in both symptoms being eliminated.

Now, I'm not saying that your mod didn't disable the VCM, but I don't know with 100% certainty that it did. All I know is that the 2 symptoms of VCM activation went away and that your milage changed by 1 MPG (which could be noise).

Is there any way of actually monitoring all three cylinders with and without the mod and showing beyond a shadow of a doubt that all three cylinders shut down without the mod and that all three cylinders never shut down, never changed their timing, never changed at all, with the mod?

In other words, the elimination of the symptoms makes us assume the disease has been cured, but we haven't really looked for the elimination of the actual disease itself. Cancer has been known to fool doctors into thinking it was eliminated because of the lack of symptoms, when it reality all it did was alter itself without really going away.
There may be doubt in your mind but there's no doubt in mine. Anyone that has experienced VCM vibrations knows exactly what it is and why it happens. The engine goes unbalanced when it drops cylinders. That's why they use the active engine mounts and noise cancellation. I drove it half the winter with VCM vibrations and EVERY time the vibrations started, it coincided exactly with the ECO light. The ECO light was never on without there being vibrations. Honda acknowledged the vibrations were due to VCM it in their TSB as well as Acura's TSB.

I understand your concerns. If you aren't having vibrations and still want to disable VCM (like many do), you want to know for sure that it's' not activating. A simple way would be to put a voltmeter on the signal input to the VCM solenoid and somehow wire it into the cabin for a test drive. I'm not going to because I'm convinced.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #34 ·
Verbatim, what resistor ohm and watt rating did you settle on for your production piece? I have an 05, and am willing to add a resistor to the existing ect1 circuit wiring (well out if warranty here)...just curious what resistor to use.
82 Ohms.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #35 ·
Everything I've read in your threads so far sounds like it's a smashing success. I think the real test is what happens when you go through stop and go traffic in mid August in Arizona or somewhere where the outside air temps can get to 110+ degrees. Will it affect drivability or cooling ability of the vehicle then? That's the scenario I'd like more feedback or comments on.

I'm just curious if that ECT1 reading does anything else besides signal VCM to activate at temp. I would think that reading would be used for something else besides VCM and whatever it affects may not be visible until ambient temps get really high. Any ideas?
I do wish I had more data to know for sure what temp the engine can get to when idling in traffic in Death Valley. I'm hoping the cooling system is efficient enough not to let it go too high above normal.

It's used to monitor engine temperature, obviously to give you a dash gauge and warnings if it overheats. I've seen no evidence of any other system being affected. You could argue that it affects A/F ratio but I believe any effect would be small if there's one at all. the ECU will use IAT as it's primary determiner as far as temperature goes for the a/f ratio.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #36 ·
Hopefully the guy that's a Honda tech will chime in here soon. For me, the fact that this appears to be working is good enough reason for me to lay some a few bucks and try it out. I've got none of the vibration symptoms that have been an issue for some of you but even so, I know that it has had some effect on the engine already. When I changed out my plugs at 59k kms, the rear one closest to the drivers side had a tip that was much shorter and worn / oily than all the others. Rear bank plugs definitely looked a little 'wet' compared to fronts which were dry.

I suppose one way to check (but it would require time and some investment) would be to change the rear bank spark plugs and drive it with this mod installed. Then after a specified period of time, pull them and see if they look 'wet'. If they are 'dry' you could make a correlation that the mod appears to have had a positive effect on the plugs and that this *could be* because of the VCM being disabled.
A honda tech bought one from me already. :)

i had thought about that already with the plugs. Unfortunately, I didn't think to do it before I installed it for a while, so I've decided to wait another month or so to give it some run time anyway, pull the plugs, inspect, replace all and check to see what they look like again later.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #37 ·
ASFAIK, the ECO light and VCM are not related. They are closely coupled as VCM would be on while in ECO mode mostly but they are distinct. To play a devil's advocate, the fact that ECO is not turning on is a tell tale giveaway that the resistor indeed is sending a not-warmed up voltage to the PCM. I don't know what is better, running with the PCM thinking the vehicle is not warmed up or running VCM. There are several long term carbon related issues with running rich which is what the vehicle runs when not warmed up.
I don't believe the ECU will demand a rich situation for very long past startup. At just 15 degrees below normal operating temp, I highly doubt that it would be dumping fuel into the cylinders. I've seen no excessive fuel consumption either, just what you would expect without VCM.


If given a choice, I would disable the VCM with the CEL light ON way as that should only impact the VCM. Yes. The ECO light does not come on in that case as well but that is because of the CEL being on. At least we know for a fact the car won't be running rich in that scenario.
On the pilot, disabling the VCM with CEL on also disables VTM-4 as well. Others report it also disables VSA. One major drawback of this that most seem to forget is that with the CEL on constantly, you have no clue if something else goes wrong because the CEL is already on... or you may miss it. you can check regularly with an OBD tool, but you might be too late if it's serious.

OP's Pilot is a 2012 model. Which has the VCM2 system. We in the 3rd gen have both VCM (2005 - 2007) and VCM2 (2008 - 2010) depending on the model year. So, more testing would be needed for the older VCM system. :)
I would not offer what I have for the older generation for two reasons. 1. the connector is different and I'd have to order some in. 2. It hasn't been tested like you say. I believe I said that in another post?
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #39 ·
Again just curious - how did you arrive at this value? Was it trial and error? I'm just wondering what the range of resistors was because it would be interesting to see your research in terms of how you got there. And when can I buy one? :D
read post #16.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #40 ·
Again just curious - how did you arrive at this value? Was it trial and error? I'm just wondering what the range of resistors was because it would be interesting to see your research in terms of how you got there. And when can I buy one? :D
Oh, and as far as when you can buy one goes, they're on sale now, but I'm not allowed to post a classified here yet, and presumably nothing about selling on regular threads. I think it's ok to say you can just PM me though.
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #44 ·
Did eBay. Reached my selling limit for the month in a couple hours. Until I prove myself as a legit seller they won't raise my limit.

Kijiji is ok but no onllne payment forms. I've just been sending PayPal invoices or doing email money transfers (Canada only for the last one).
 

·
Registered
Joined
·
227 Posts
Discussion Starter · #50 ·
Is there a detailed DIY with pics. etc?
Thanks.
I don't have a detailed DIY for making the harness itself. The male connectors are only available from China in quantities larger than 100 and you need to buy a special crimp tool. If anyone wants to see the 4 page installation manual with pics on how to install it, PM me with your email address and I'll send it to you.

Attached are pics from the manual.

Wire Technology Cable Electronic device Electronics accessory
Auto part Engine Automotive fuel system Vehicle Fuel line
Auto part Engine Automotive engine part
Auto part Fuel line Engine Automotive fuel system Automotive engine part
Auto part Engine Automotive fuel system Fuel line Vehicle
 
1 - 20 of 190 Posts
Top