S-VCM Problem. Time to remove?

Vanguard · Mar 19, 2021

I bought and installed an S-VCM last fall on my 2013 Odyssey. Worked flawlessly until last week. My daughter borrowed the van and mentioned it was idling very rough. When she brought it back, I noted that it would suddenly drop rpm and almost stall when idling. It would intermittently drop rpm too when accelerating. I checked the engine, swapped engine filter, cleaned MAF and the problem seemed to go away. I didn't suspect the S-VCM at this time.

Fast forward about a week and the issue has returned. I was waiting in line at a drive-thru when the rpms suddenly dropped, almost stalling, then would come back to idle. Repeat. It would start running fine again for a few minutes, then rpms would start dropping again. The van never stalled and was OK to drive home, just a little rough, with rpm bouncing around a little. One thing I did notice on the way home was the ECO light coming on (blinked on briefly several times), which I haven't seen since install of the S-VCM. Surprised to see the ECO light, I looked at the engine temp gauge and it was very low, just barely above minimum. Too low considering how long I had been driving, and definitely not where I am used to seeing it with the S-VCM. From my understanding, I wouldn't expect to see the ECO light come on at that temp reading either.

Has anyone else experienced this with S-VCM? Any ideas what the issue might be? Am I correct to assume this is S-VCM related? I am going to remove it for the next while to confirm it resolves the issue.

Jfaas · Mar 19, 2021

If you remove the s-vcm and the problem persists, you may have a faulty oxygen sensor.

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2011.2017.odyssey · Mar 19, 2021

check the air intake tube for splits/ cracks.
seems to be common on these, esp ones where the motor mounts are finished thanks to VCM activation.

based on a recent post, the part is 20USD at the dealer or about 200CAD
😂

Batvette · Mar 25, 2021

Your economy must have tanked big time up there I haven't heard of an exchange rate that unfavorable in many years.

phattyduck · Mar 19, 2021

Easy to check by removing the S-VCM. Inspect the wiring in that vicinity and the intake tube while you are in there.

-Charlie

Vanguard · Mar 19, 2021

Thanks for the suggestions. So the intake tube and oxygen sensor sound like the most likely culprits, aside from a possibly faulty S-VCM. Would a cracked tube or faulty sensor cause the low engine temp reading, or the ECO light to go on with the S-VCM installed? Still trying to make sense of what those clues are telling me.

Jfaas · Mar 19, 2021

Vanguard said:
Thanks for the suggestions. So the intake tube and oxygen sensor sound like the most likely culprits, aside from a possibly faulty S-VCM. Would a cracked tube or faulty sensor cause the low engine temp reading, or the ECO light to go on with the S-VCM installed? Still trying to make sense of what those clues are telling me.

An o2 sensor will cause rough/erratic idle conditions and possible stalling. I have not heard of engine temp associated with o2 sensor. I know nothing about what activates the eco light.

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2011.2017.odyssey · Mar 19, 2021

+1 on Jfaas suggestion of removing the s-vcm, and see what happens.

l havnt seen a post where a vcm muzzler caused an issue outside of a check engine light due to improper installation.

but hey anything can happen, and since you are implicating the s-vcm, remove it and observe.

2011.2017.odyssey · Mar 19, 2021

low engine temp is how the vcm muzzler tricks the pcm to not activate vcm.

how low are we talking about here? I get slightly above/between 1/4 and 1/2 on the temp gauge with the vcmuzzlerii installed.

Vanguard · Mar 19, 2021

I am talking low. Normally it runs about the same with my S-VCM as with your VCMuzzlerII. Between 1/4 and 1/2. Today when I was having issues and the ECO light came on, I immediately looked at the temp gauge because I know that is how the S-VCM prevents ECO from kicking in. The temp gauge was showing just above minimum reading, maybe 1/8. This was after a good 30-45 minutes of driving. Very odd.

2011.2017.odyssey · Mar 19, 2021

idle and air fuel ratio mixture are based on engine temp.

pull the s-vcm off and see what temp reading you are getting, plug in an obdii reader to get real numbers.
its possible the sensor or s-vcm is toast.

Vanguard · Mar 20, 2021

Pulling off the S-VCM and checking sensors/wiring, air tube tomorrow. The issue has only occurred twice now with a week in between, so it may take some time to know if it is the S-VCM for sure. If it happens again right away after I take off the S-VCM, at least I can rule that out.

I tried ODB2 reader tonight. No codes. No codes when this last happened a week ago too.

phattyduck · Mar 19, 2021

What is confusing is that the ECO light is turning on but the temp reads low - those should be mutually exclusive...

-Charlie

Vanguard · Mar 20, 2021

This is what got me thinking something is up with the S-VCM. It didn't make sense that the ECO should come on at all if the S-VCM is working properly, nor with the temp gauge dislaying so low. The engine was fully warmed up, but temp gauge was barely registering.

2011.2017.odyssey · Mar 19, 2021

it could be worse and the pcm is failing, but with the absence of a check engine light, not likely.

Vanguard · Mar 20, 2021

So I took the van out for a drive this morning. No issues, ran fine and temp gauge looked correct. I decided to take the S-VCM off for a week or two anyways, just to see if the problem returns or not. Took the van for another drive. I must say, after getting used to the van muzzled, having VCM active again sucks. Temp was good and rpm smooth still.

When I was disabling the S-VCM, I checked all sensors/wiring and everything looked good. I also checked the air tube and it does have a crack, so it is getting replaced.

The rubber of the hose actually feels very dry and brittle, like it could easily split if I put any pull on it (I am giving it a little pull in the pic to make the crack more visible). So called dealership and part 17228-RV0-A00 is now on order. $30.76 CAD. The crazy thing was the clamps for each end. They were $35 and $50 respectively. Not sure why, they look like basic hose clamps, although they are sized for this application (they are marked for how tight they should be fastened). I asked if they needed to be ordered too, but the parts rep didn't see any need.

So, I will replace the air tube in a few days once it comes in. I will give it a week or two without S-VCM. If all good, I will reinstall the S-VCM and see what happens.

Ed2013 · Mar 23, 2021

Nice! Keep us posted.

Vanguard · Mar 24, 2021

So the new air tube came in this morning. Took about 20 minutes to swap it out. I felt confident that the cracked tube had to be the cause, so I went ahead and re-enabled the S-VCM. Really can't stand having the VCM active. Did a quick trip to the grocery store and back home. As soon as I pulled into the driveway, the engine started acting up again. So, it wasn't the cracked tube and I unfortunately failed to rule out the S-VCM. Could be something else completely too. Still no codes. I guess I will have to disable the S-VCM again tomorrow.

Again, the rpm starting bouncing (it would drop from 1000 to around 500, then back up to 1000 for about 4 seconds, repeat) very rhythmically. Sounded like it was going to stall, then would return to normal idle. It wasn't erratic, there was a pattern. It never surged above 1000 rpm either. At the same time, the temp gauge dropped almost all the way to bottom, then back up to normal operating temperature. I could see the gauge slowly move down then back up with a slight fluctuation, the total movement from "normal" temp to bottom and back taking about 15 or 20 seconds. No ECO light this time.

The other thing I noticed is that this happens after some driving and coming to a halt. The first two times happened while waiting in a drive-thru lineup. Today was after a drive to the grocery store. It started up as soon as I stopped in my driveway.

I managed to get video of the rpm bouncing, but the temp gauge had already finished moving around by the time I thought to record it and grabbed my phone. At least I have that to show my mechanic if I give up and bring it to him. Nothing worse than a problem you can't reproduce at a given time.

So, disabling S-VCM again for now and seeing what happens next. If anyone else has some troubleshooting ideas, please share.

Thanks!

phattyduck · Mar 24, 2021

Take a close look around the engine bay for chewed wires from mice/rats/etc. They like the insulation on the wires and the warm, dark engine bay. Broken or near broken wires could lead to some funky problems.

-Charlie

Vanguard · Mar 25, 2021

Out for a drive today, hadn't disabled S-VCM again yet. Came to a red light and noticed the temp gauge dropping. Seemed odd as the engine was running fine. Sure enough, after it sat at lowest reading on temp gauge for half a minute, the engine started acting up again. Temp gauge went back up, but was still fluctuating a bit. ECO light was coming on too. I decided to pull onto a side street and check it out. Turned the engine off for a few minutes, started back up. Still bouncing rpm. Turned it back off, unplugged S-VCM and checked all around for any signs of loose or damaged wires. All looked good. Started van back up and running perfect again, although I have a CEL now. Probably related to pulling the S-VCM, but I will check with my code reader when I get back home. On the plus side, the CEL is preventing VCM from activating.

So I am really starting to lean towards this being an issue with the S-VCM module. Will have to wait longer and see if this issue occurs with S-VCM disabled.

Edit: the CEL cleared before I got back home and VCM became active again. Oh well.

2011.2017.odyssey · Mar 26, 2021

Vanguard said:
Out for a drive today, hadn't disabled S-VCM again yet. Came to a red light and noticed the temp gauge dropping. Seemed odd as the engine was running fine. Sure enough, after it sat at lowest reading on temp gauge for half a minute, the engine started acting up again. Temp gauge went back up, but was still fluctuating a bit. ECO light was coming on too. I decided to pull onto a side street and check it out. Turned the engine off for a few minutes, started back up. Still bouncing rpm. Turned it back off, unplugged S-VCM and checked all around for any signs of loose or damaged wires. All looked good. Started van back up and running perfect again, although I have a CEL now. Probably related to pulling the S-VCM, but I will check with my code reader when I get back home. On the plus side, the CEL is preventing VCM from activating.

So I am really starting to lean towards this being an issue with the S-VCM module. Will have to wait longer and see if this issue occurs with S-VCM disabled.

Edit: the CEL cleared before I got back home and VCM became active again. Oh well.

it does sound like its a defective unit. which is a first for me to see here.

AndrewS816 · Mar 26, 2021

Ping Reny at S-VCM as I'm sure he'll help you out and would be interested to see what's up with this particular unit; if in fact it's the culprit (which it's sounding more and more like it is).

auggie721 · Mar 28, 2021

Having similar issues as OP - temp fluctuating between normal and cold wildly in real time as I watch, RPM's would drop like the car was stumbling when this happens. It's been almost 2 years exactly since I installed my S-VCM. Disconnected it after latest episode and took for a long test drive and problems disappeared immediately. So just adding my $0.02 that I think the S-VCM is the culprit here.

WiiMaster · Mar 29, 2021

When did you buy your S-VCM? Maybe you and OP can compare purchase dates and see if it's just a general manufacturing defect or if it's just with a certain batch.

AndrewS816 · Mar 29, 2021

Have you guys contacted S-VCM to see what they have to say? If these things are prone to failure that would be good to know and document so we can recommend to the community to go with another option but I think some people have had theirs on for years with no issues.

Hey, your car is acting up, you take it off, it stops acting up; you've isolated the issue! Not disputing that but if they're made aware of the problem maybe they'll help you out on a new device and want to see what on their old design failed so they can take corrective action.

Good luck!

Vanguard · Mar 30, 2021

I have been driving without issue since I disabled the S-VCM last week. I am sure it is the S-VCM at this point. I sent the manufacturer a message via their website when this first occurred to see if they had any trouble-shooting suggestions. I have not heard anything back. I purchased mine on August 21, 2020, so definitely within the 1 year warranty period I guess it is time to start trying to figure out how to go about making a warranty claim with them.

Vanguard · Apr 10, 2021

Update: received my replacement unit yesterday. No hassle getting it replaced under warranty (very good service). Installed it today, but haven't tested it yet. The van has been running fine since disabling the old controller.

A pic of the two controllers, old on left, new on right. No appreciable difference. No noticeable wear or tear on the old one either.

AndrewS816 · Apr 11, 2021

Glad they got you a warranty unit, let us know how it goes. Was the resistor "pack" (not sure what to call this bundle) sitting on the engine block cooking? Hard to say what might have gone wrong but thanks for posting and keeping us up to date.

We have an S-VCM "Custom" so the resistor pack is inside the car, hopefully that will allow it to last a good long time. That said, I wouldn't recommend this option with the On/Off capabilities as 1) it's unnecessary and 2) the installation was a total PIA!!!

Vanguard · Apr 11, 2021

AndrewS816 said:
Was the resistor "pack" (not sure what to call this bundle) sitting on the engine block cooking? Hard to say what might have gone wrong but thanks for posting and keeping us up to date.

No, the resistor sits suspended in air, not touching anything. You zip-tie the two cables on the controller to the existing cable to keep everything snug and safe. There are not too many ways to go wrong with the install as long as you use the zip ties to secure everything. The engine does give off a fair amount of heat in this area, so I too wondered if that might be the cause, but all other cabling/sensors would be exposed to this same heat.

I did take the van out for a drive last night and the new controller worked great and no engine/temp gauge issues. So nice to have VCM disabled again.

jnissen · Apr 11, 2021

Hopefully you sent the old unit back to them for analysis. Probably heat related loss of memory inside the unit micro. Unless they opted for a specific automotive grade part that’s a common problem in electronics.

Vanguard · Apr 11, 2021

I haven't sent it back, but I did offer to. No reply received yet.

The more I think about it, heat seems a possible culprit. The issue always started while we were out driving around (full operating temp), but only when we came to a stop. Like in a drive thru or at a red light, where heat could accumulate. It never started while the van was actually moving. Once started though, it would continue with the van moving. However, next time we would use the van (after sufficient cool down perhaps) it would work fine again.

Vanguard · Jun 8, 2021

Update: it has been almost 2 months with new S-VCM installed and no further issues. I am pretty sure it was a heat-related failure. Hopefully the second one holds up better. I might try to wrap it in some sort of insulation.

fatlard · Nov 8, 2021

Old post but resurrecting it for further discussion.

I installed S-VCM on my 2008 van since April 2019.... recently I noticed my that the temperature gauge on my dash drop to C (Low) while on a drive when going 55-70 miles and hour and also once while idling. It would stay at low a couple of minutes and then go back to normal. Normal being is slightly below middle of the gauge. I been chasing RPM drops while idle as well .. .and cleaned throttle body and order a replacement air intake tube due to cracking as you seen in yours.

Now I am wondering if my rpm issues and temperature gauge dropping to C has to do with the S-VCM.

Will be unplugging and testing this theory out soon..

surgeon · Nov 8, 2021

Make sure you contact SVCM support too. As you do your test, and additional suggestions by them, you can do those at the same time. If not you might have to repeat something again. When I had an issue, I had to debug and then a replacement was sent.

fatlard · Nov 8, 2021

S-VCM support is definitely good. I emailed them on a Sunday and they will be sending another one to test. I offered to send it back so he can test but he said to save on shipping he will just send me another. I covered the shipping which is very reasonable offer since it was out of warranty. Shipping was a bit high at $27 but it is ok.

vtec555 · Nov 17, 2021

S-VCM Problem. Time to remove?

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