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Discussion Starter · #1 ·
Yesterday I installed the S-VCM and coolant temperature reported consistent on the ScanGauge at 164, so the S-VCM is obviously working as designed. Over the last few weeks, nominal normal coolant temperature was around 170-174 but that's been late-winter conditions.

Engine response and overall "feel" is a night-and-day difference, so I'm now kicking myself for waiting 4 months to do it. I'm convinced that it's better for the engine as a whole power unit since 50% of the engine isn't doing all the work moving the Pilot AND working extra to overcome vacuum pressure in the rear cylinder bank. Mileage is about the same but smoothness and balance are dramatically better.

My question is this....if S-VCM is fooling the ECU on the coolant temperature, I'm assuming that the radiator fans will never engage. Yes, I understand that supposedly S-VCM will pass the "true" temperature to the ECU if there's a potential of overheating, in which case VCM is engaged and (I'm assuming here) the radiator fans will engage and the ScanGauge will then spike the fWT reading to the true temperature.

Has anyone:

1) Noticed the radiator fans engaging with S-VCM engaged under normal operation? ("Normal" being the operative word).

2) Experienced an overheating condition where S-VCM disabled and VCM engaged, thus causing the radiator fans to turn on?

I get the logic behind the S-VCM operation, but am just thinking it forward towards a bad-case/worse-case scenario.

I suppose that on a really hot day I could pull the fuse out of the S-VCM and force the radiator fans on, but it also seems that this would be a scenario S-VCM should be designed for.

Thoughts as we approach the summer and increasing ambient temps?

Thanks, everyone!
 

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Yesterday I installed the S-VCM and coolant temperature reported consistent on the ScanGauge at 164, so the S-VCM is obviously working as designed. Over the last few weeks, nominal normal coolant temperature was around 170-174 but that's been late-winter conditions.

Engine response and overall "feel" is a night-and-day difference, so I'm now kicking myself for waiting 4 months to do it. I'm convinced that it's better for the engine as a whole power unit since 50% of the engine isn't doing all the work moving the Pilot AND working extra to overcome vacuum pressure in the rear cylinder bank. Mileage is about the same but smoothness and balance are dramatically better.

My question is this....if S-VCM is fooling the ECU on the coolant temperature, I'm assuming that the radiator fans will never engage. Yes, I understand that supposedly S-VCM will pass the "true" temperature to the ECU if there's a potential of overheating, in which case VCM is engaged and (I'm assuming here) the radiator fans will engage and the ScanGauge will then spike the fWT reading to the true temperature.

Has anyone:

1) Noticed the radiator fans engaging with S-VCM engaged under normal operation? ("Normal" being the operative word).

2) Experienced an overheating condition where S-VCM disabled and VCM engaged, thus causing the radiator fans to turn on?

I get the logic behind the S-VCM operation, but am just thinking it forward towards a bad-case/worse-case scenario.

I suppose that on a really hot day I could pull the fuse out of the S-VCM and force the radiator fans on, but it also seems that this would be a scenario S-VCM should be designed for.

Thoughts as we approach the summer and increasing ambient temps?

Thanks, everyone!
1) The fans still work fine. They are primarily controlled by a 2nd temp sensor (ECT2, S-VCM modifies the signal of ECT1).

2) Nope.

3) If you’re really worried about summer remember that the AC kicks on the fans too.

Ive had it on our 2013 for a while now. Plug and play and forget it’s on there. Nothing to worry about. :)
 

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Absolutely no issues here either. The fans are also controlled by ECT2 located in the lower rad tank. Also when the temp reaches 205°F the S-VCM goes into bypass and ECT1 functions normally sending the true signal to the Gauge and PCM so that all warnings will activate if the temp keeps getting higher.
 

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The only thing a VCM disabling device will do is make it more difficult to diagnose what's causing an overheating problem. It will never be the cause.
For your peace of mind...,
In the morning with the engine cooled down, test the cooling fans. Do the cooling fans come on with the use of the AC?
When returning home when you know the engine has warmed to operating temperature, turn the AC off. Do both cooling fans come on due to engine temperature?
If cooling fans are not functioning properly, it needs to be determined why. Fan motor(s) could be burned out, fuse or relay.
Has the coolant been replaced?
Is there any leaks or rust in the system?
I disconnect S-VCM to run diagnostics to insure fans are coming on and going off at the correct engine temp. Once I know all is well, I reconnect S-VCM when the engine is cool.
 
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Discussion Starter · #5 ·
Thanks, everyone. I don't have any problems that require diagnosis/resulting. I was just trying to get a sense for any downstream impacts of the S-VCM on the cooling system. It sounds as if everything will be operating as designed which is good news.
 

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On the subject of ECT2, does anyone know if Scan Gauge II can read that? I tried some of the codes they emailed me but they did not seem to work. Their engineer is/was on vacation so I need to give them a call back to see what he says. I guess he owns a Pilot gen 3 as well.
 

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Discussion Starter · #8 ·
On the subject of ECT2, does anyone know if Scan Gauge II can read that? I tried some of the codes they emailed me but they did not seem to work. Their engineer is/was on vacation so I need to give them a call back to see what he says. I guess he owns a Pilot gen 3 as well.
If you ever get those extra X-Gauge codes, please post them! I'd love to see the difference between the ECT1/ECT2 reported temps on the ScanGauge!
 

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See post #3 in this thread/link. CT2 (cold rad tank) can easily be 100*+ below CT1 (engine coolant).


Gen 2 2017 Ridgeline.
 

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If you ever get those extra X-Gauge codes, please post them! I'd love to see the difference between the ECT1/ECT2 reported temps on the ScanGauge!
See post #3 in this thread/link. CT2 (cold rad tank) can easily be 100*+ below CT1 (engine coolant).


Gen 2 2017 Ridgeline.
That result is similar to what I see on my Pilot and because I would see temps below 100*F while the engine was on, I figured no way that is coolant. The apparent CT2 with a warm engine would start at say 170*F then as soon as I start moving it would slowly below 100*F which is of no use. Where in the coolant system could there possibly be a coolant reading that is just over ambient? The radiator can't possibly be that efficient. I just can't literally see it being possible ever when my outdoor weather is in the 67F range. So I figured that temp sensor was reading something other than coolant.

Now I saw in the ridgeline forum someone thinks something might be reported in Celsius?

Well, this did remind me I need to call them back but for the meantime, here is what they originally sent me. What worked was when I changed the TXD to start with 10 instead of 0E.

Coolant Temp #1 (°F)
TXD: 0EF1228A10
RXF: C32200000000
RXD: 2008
MTH: 00090005FFD8
NAME: 1CT

Coolant Temp #2 (°F)
TXD: 0EF1228A10
RXF: C32600000000
RXD: 1808
MTH: 00090005FFD8
NAME: 2CT

If those don't work, try changing the TXD to start with 10 instead of 0E.

Coolant Temperature 1 (Degrees Fahrenheit)
TXD: 33F10167
RXF: 044105670000
RXD: 3008
MTH: 00090005FFD8
NAME: CT1

Coolant Temperature 2 (Degrees Fahrenheit)
TXD: 33F10167
RXF: 044105670000
RXD: 3808
MTH: 00090005FFD8
NAME: CT2
 

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That result is similar to what I see on my Pilot and because I would see temps below 100*F while the engine was on, I figured no way that is coolant. The apparent CT2 with a warm engine would start at say 170*F then as soon as I start moving it would slowly below 100*F which is of no use. Where in the coolant system could there possibly be a coolant reading that is just over ambient? The radiator can't possibly be that efficient. I just can't literally see it being possible ever when my outdoor weather is in the 67F range. So I figured that temp sensor was reading something other than coolant.

Now I saw in the ridgeline forum someone thinks something might be reported in Celsius?

Well, this did remind me I need to call them back but for the meantime, here is what they originally sent me. What worked was when I changed the TXD to start with 10 instead of 0E.
The radiator IS that efficient.....especially in cool ambient temps with a high volume of airflow thru the rad. Under those driving conditions, the t-stat is only opening a sliver and closing again. The t-stat "hovers" in an infinite number of positions between closed and max open. When the t-stat is closed there is virtually no coolant flow thru the rad so the cold rad tank, where the CT2 sensor is located, will be close to ambient temp, depending on driving conditions.

Again, CT2 proves how efficient the radiator is.
 
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The radiator IS that efficient.....especially in cool ambient temps with a high volume of airflow thru the rad. Under those driving conditions, the t-stat is only opening a sliver and closing again. The t-stat "hovers" in an infinite number of positions between closed and max open. When the t-stat is closed there is virtually no coolant flow thru the rad so the cold rad tank, where the CT2 sensor is located, will be close to ambient temp, depending on driving conditions.

Again, CT2 proves how efficient the radiator is.
Thanks for the explanation. I will monitor it while driving. I pretty much dismissed it when I saw the temp dropping significantly thinking it was maybe the air intake temp or something.
 

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PlPl,
Here's your cues for the beating a dead horse emoji LOL
 

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Yesterday I installed the S-VCM and coolant temperature reported consistent on the ScanGauge at 164, so the S-VCM is obviously working as designed. Over the last few weeks, nominal normal coolant temperature was around 170-174 but that's been late-winter conditions.

Engine response and overall "feel" is a night-and-day difference, so I'm now kicking myself for waiting 4 months to do it. I'm convinced that it's better for the engine as a whole power unit since 50% of the engine isn't doing all the work moving the Pilot AND working extra to overcome vacuum pressure in the rear cylinder bank. Mileage is about the same but smoothness and balance are dramatically better.

My question is this....if S-VCM is fooling the ECU on the coolant temperature, I'm assuming that the radiator fans will never engage. Yes, I understand that supposedly S-VCM will pass the "true" temperature to the ECU if there's a potential of overheating, in which case VCM is engaged and (I'm assuming here) the radiator fans will engage and the ScanGauge will then spike the fWT reading to the true temperature.

Has anyone:

1) Noticed the radiator fans engaging with S-VCM engaged under normal operation? ("Normal" being the operative word).

2) Experienced an overheating condition where S-VCM disabled and VCM engaged, thus causing the radiator fans to turn on?

I get the logic behind the S-VCM operation, but am just thinking it forward towards a bad-case/worse-case scenario.

I suppose that on a really hot day I could pull the fuse out of the S-VCM and force the radiator fans on, but it also seems that this would be a scenario S-VCM should be designed for.

Thoughts as we approach the summer and increasing ambient temps?

Thanks, everyone!
Ok I get the theory behind all this, but What would cause the engine to overheat using this device? ( I know the device does not cause overheating) providing and let’s for sake of argument, that EVERYTHING IS IN ORDER, and WORKING AS IT SHOULD? Crazy ass driving, towing something (vehicle as oem cooler) driving up Mt. Washington,? What? If someone drives normally 65 mph, keeps vehicle well maintained, fans are working, new coolant, you get the picture, I’ve never ever, had a vehicle go into overheating, never. I find this topic of overheating to be a deal breaker for ANY MGF’s device, that I might just leave the device off, so if someone can tell me how driving sensibly, what other conditions would cause overheating, BARRING the examples I’ve discussed ( everything up to snuff) using the SVCM installed.
 

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I can’t speak regarding the S-VCM because I use the VCMTuner II. I occasionally ground the green wire to disable the disabler and allow the ScanGauge to return to displaying actual ECT. Using a male/female spade connector on the green wire takes about 5 seconds to switch back and forth. I also monitor CT2 which is unaffected by the VCMTuner II. If CT2 were to exceed 205F, you may have a problem in the efan circuit.

It’s easy to force 205F CT1 and CT2 in 100F+ ambient, a/c off, idling. That’s when you should heat the efans turn on and ECT will drop rapidly.
 

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Ok I get the theory behind all this, but What would cause the engine to overheat using this device? ( I know the device does not cause overheating) providing and let’s for sake of argument, that EVERYTHING IS IN ORDER, and WORKING AS IT SHOULD? Crazy ass driving, towing something (vehicle as oem cooler) driving up Mt. Washington,? What? If someone drives normally 65 mph, keeps vehicle well maintained, fans are working, new coolant, you get the picture, I’ve never ever, had a vehicle go into overheating, never. I find this topic of overheating to be a deal breaker for ANY MGF’s device, that I might just leave the device off, so if someone can tell me how driving sensibly, what other conditions would cause overheating, BARRING the examples I’ve discussed ( everything up to snuff) using the SVCM installed.
What I've been told is that S-VCM is supposed to alert you if the engine should happen to overheat.
 

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I believe (not 100% positive) the S-VCM “Custom” is the model that has the “alert” feature. My guess is the alert is audible.🤷‍♂️
 

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For what it’s worth, I installed the SVCM yesterday, today ambient temperatures were 93 deg. high humidity. I drove up and down and all around in the Adirondacks mountains a good 100 mile ride into Vermont and back. Stopped at my son in laws, a certified master tech with Mercedes, Porsche, and Ferrari’s, he used his high tech equipment and the temps were: coolant 176-179 deg. Transmission temp. 182 deg. So I’m gonna, stop this wringing of the hands over this overheating issue, Im finally putting this to bed, permanently!!!
 
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