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Discussion Starter · #1 ·
Hi guys,
I am wondering if there is a way to quickly disable S-VCM without uninstalling, I am talking about scenarios like a day long high way drive.
I understand there is a custom model which comes with a switch, but I have the regular model.
Will it be as easy as to disconnect the power cable to the battery terminal?
Thanks.
 

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Hi guys,
I am wondering if there is a way to quickly disable S-VCM without uninstalling, I am talking about scenarios like a day long high way drive.
I understand there is a custom model which comes with a switch, but I have the regular model.
Will it be as easy as to disconnect the power cable to the battery terminal?
Thanks.
why would you want to disable it for a highway drive?
 

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Hi guys,
I am wondering if there is a way to quickly disable S-VCM without uninstalling, I am talking about scenarios like a day long high way drive.
I understand there is a custom model which comes with a switch, but I have the regular model.
Will it be as easy as to disconnect the power cable to the battery terminal?
Thanks.
Pull the fuse
 

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S-VCM fuse? I don't know the default behavior of S-VCM if you remove power, but I do know if you remove or insert it, the PCM will detect an "sudden" implausible temp change from the ECT sensor and set a code unless you wait until the car has cooled down (guessing 4+ hours). Otherwise, the car will drive fine until the code clears (after a cool down and start), but until then the PCM may have a fault strategy that effects the engine, transmission, radiator fans, etc; i.e. impacting any MPG benchmarking.
 

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I can’t think of a single reason that I would want to disable my S-VCM, especially on the highway or a while the cruise control is on.
 
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S-VCM fuse? I don't know the default behavior of S-VCM if you remove power, but I do know if you remove or insert it, the PCM will detect an "sudden" implausible temp change from the ECT sensor and set a code unless you wait until the car has cooled down (guessing 4+ hours). Otherwise, the car will drive fine until the code clears (after a cool down and start), but until then the PCM may have a fault strategy that effects the engine, transmission, radiator fans, etc; i.e. impacting any MPG benchmarking.
Mine has an inline fuse on the power. I pull it now and then to run the car stock.
 

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I can’t think of a single reason that I would want to disable my S-VCM, especially on the highway or a while the cruise control is on.
Ours seems to run better around town with it turned off. Occasional "weak startup" and we actually had a cylinder misfire - not enough to blink the cel but a 2 count on a misfire counter. Pulled the plug and coil. Checked resistance on both. Plugs in were in great shape as was the coil. Turned VCM back on (S-VCM off, by pulling the fuse) and hasn't happened again. We'd run the S-VCM for years without issues, but this year just started acting slightly strange... but the strangeness goes away when you take S-VCM out of the equation.

With the high gas prices and the fact my wife only drives city + our exclusive use of synthetic oil with zero detectable consumption... we've left ours off right now. If I was going to to use it on a road trip with steady speeds and cruise control I'd for sure throw the S-VCM fuse back in. With that said - the Audi has become our road trip machine which it truly excels at. Chances of the Pilot going more than 20 miles from home are slim to none these days.
 
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S-VCM fuse? I don't know the default behavior of S-VCM if you remove power, but I do know if you remove or insert it, the PCM will detect an "sudden" implausible temp change from the ECT sensor and set a code unless you wait until the car has cooled down (guessing 4+ hours). Otherwise, the car will drive fine until the code clears (after a cool down and start), but until then the PCM may have a fault strategy that effects the engine, transmission, radiator fans, etc; i.e. impacting any MPG benchmarking.
The default with the fuse removed or power wire disconnected, is a full bypass of the S-VCM module which will result in the actual ECT1 temp signal going to the PCM. You are correct about powering it up again, as the car should be cooled down prior to establishing power or you risk setting a fault code.
 

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I took my fuse out yesterday for my yearly long drive from NY to Florida. I keep the car with the A/C on the entire trip and I want an accurate temperature gauge. Yes I'll be using cruise at 85mph on 3 cylinders back and forth. When I get back from my trip I'll put the fuse back in (cold). I won't chance a problem with the car temperature with the entire family in the car. If there was a way to see it using CarScanner with my Veepeak OBDCheck Scan Tool I would keep it operational. This is what I see though....
Font Material property Screenshot Number Document
 

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I took my fuse out yesterday for my yearly long drive from NY to Florida. I keep the car with the A/C on the entire trip and I want an accurate temperature gauge. Yes I'll be using cruise at 85mph on 3 cylinders back and forth. When I get back from my trip I'll put the fuse back in (cold). I won't chance a problem with the car temperature with the entire family in the car. If there was a way to see it using CarScanner with my Veepeak OBDCheck Scan Tool I would keep it operational. This is what I see though.... View attachment 160343
It’s questionable how accurate that temp gauge is in a first place. I’m watched the temps whenever the car was warming up (without SVCM) and it got up to the middle (where it stays at all the time) and ECU temp was around 160. temp gauge never moved again even though actual ECU was 190 or so.
 

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The temp gauge on most modern cars is a "normalized" needle position that the PCM sets, so that the driver is not distracted (or alarmed) by the normal fluctuations in actual coolant temp as you drive, sit at lights, AC on or off, etc. The temp gauge on my newly acquired '20 moved an undetectable amount whether the S-SVM was installed or not (actual coolant temp 197F without). I suspect that when it was actually overheating the gauge would suddenly jump up to HOT.

BTW, your scan tool screen snapshot shows the reported coolant temp 165.2F in this case. So was this snapshot with S-VCM disabled (fuse removed) and the car fully warmed up?
 

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The temp gauge on most modern cars is a "normalized" needle position that the PCM sets, so that the driver is not distracted (or alarmed) by the normal fluctuations in actual coolant temp as you drive, sit at lights, AC on or off, etc. The temp gauge on my newly acquired '20 moved an undetectable amount whether the S-SVM was installed or not (actual coolant temp 197F without). I suspect that when it was actually overheating the gauge would suddenly jump up to HOT.

BTW, your scan tool screen snapshot shows the reported coolant temp 165.2F in this case. So was this snapshot with S-VCM disabled (fuse removed) and the car fully warmed up?
No the SVCM was active at that screenshot. I was hoping to be able to view another type of "sensor" somewhere in the CarScanner app that would show ect2 but I didn't come up with anything. I know the ScanGauge can do it but I'm not spending that amount of cash to see ect2.
 

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Yeah, agree the radiator coolant sensor won't tell you much as it fluctuates a lot depending on ambient temp, fans running, engine load...

I guess, really, you have to weigh the long term impact of the Honda VCM on piston rings, oil consumption, engine mounts, vs a very modest manipulation of the coolant temp sensor reporting. S-VCM appears to have been well designed for reporting over-temp, and even a fail safe operation should it lose power, and of the embedded controller within, should it go stupid. A catastrophic failure of S-VCM (or VCMMuzzler for that matter), would show up as a grossly low or high engine temp, which the PCM would detect and set the check engine light and code as an "implausible value".

Further, you'd see this on the dash temp gauge. On the whole, S-VCM (or VCMMuzzler) are very very low on the risk scale, and the benefits, at least for 1st and 2nd Gen Pilots, very high. I haven't read enough reports from 3rd gen owners to understand whether Honda has solved the worst effects of piston ring & oil consumption that plagued a significant number of 1/2 Pilots, especially as the miles accumulated.
 
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If you are really concerned about engine temps when running a VCM disabler or not, the only way to get true engine temp readings is to install an accurate temp gauge and matching sensor independent of the onboard one. The dash gauge on most cars is totally useless and by the time the idiot light comes on, it's too late and you are already overheating.
 

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Just knowing how unbalanced my engine runs, the oil consumption, oil fouled spark plugs, stuck piston rings, dirty valves, the wear and tear on engine mounts, and the damage it can cause to my transmission torque converter…, nothing could convince me that there is a benefit to running without my VCM disabling device….. ever.
 

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Discussion Starter · #17 ·
Didn't expect my post to blow up like this, lol.
Thanks for the info. guys.
I was merely thinking about multi-day long drives with steady speeds which might justify setting VCM back on by disabling s-vcm.
 

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Didn't expect my post to blow up like this, lol.
Thanks for the info. guys.
I was merely thinking about multi-day long drives with steady speeds which might justify setting VCM back on by disabling s-vcm.
When the vehicle is in cruise, that’s when the VCM causes cylinder deactivation. That’s when it’s needed most.
 
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When the vehicle is in cruise, that’s when the VCM causes cylinder deactivation. That’s when it’s needed most.
Exactly, and that's when you notice the slight tach fluctuations caused by the TC going in and out of lockup mode. If you want to save the wear and tear on your TC, leave the VCM deactivated.
 
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