VCM deactivation
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As someone who works on their own vehicle, the only negative I have found concerning the use of S-VCM is it complicates diagnosing an overheating issue. To check if my cooling fans are working properly, I disconnect the device prior. Then you must be careful to only reconnect after the engine has cooled back down. I can not see that the device could ever be the cause for an overheating issue. In my opinion, using S-VCM provides way more benefit than any concern. For a fact, if I disconnected S-VCM my transmission would begin to have a torque converter clutch lock issue.
Yes, there will be negatives and there is risk involved, but you may not notice the negatives and most consider them to be outweighed by the benefits.
The disablers work by tricking the computer into thinking the engine coolant is below 167 deg F. This is the point beyond which VCM is allowed to operate by the computer. If the computer thinks the coolant temperature hasn't risen to this point, it won't enable VCM to engage. Various disablers work using different methods. Some use a simple resistor to modify the coolant temperature sensor signal to the computer. Others are powered by the battery and use a small microprocessor to dynamically modify the signal to always stay below 167 deg F, unless it detects overheating from the actual sensor signal...at which point, they're supposed to restore the actual signal to the computer so you're alerted to the situation in the instrument cluster.
Most people feel the benefits outweigh the risks, but it's misleading to say there are no risks, or no negatives to doing it. Some have reported poor driveability with VCM disabling devices, and removing the devices restored proper operation of the car. Without knowing more, none of us can verify that or diagnose the cause, but cases like that have been reported. Aftermarket devices are almost never engineered to the level of OEM stuff, and an internal failure of one of these devices could send really wonky signals to the computer (potentially causing weird driveability issues) or even draw continuous power from your battery.
The negative most people report is increased fuel use...which is a predictable side effect of doing something like this. Some say they haven't noticed a drop in fuel economy, and some even claim to be getting better fuel economy with VCM disabled, but most note a 1-2 MPG drop (which is not trivial over time...about 10%).
I'm not writing this to bad mouth these devices at all. In fact, I own one myself. It's not installed at the moment, but I've had it on the car several times and it definitely does work. I write this only to "complete the story" if you will. There are benefits and drawbacks to any change you make to something. It's up to you to decide whether the gains are worth the risks. To be certain, most on this forum will say that they absolutely do (and I'm not here speaking against that at all).
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Thank you!!!!
I've only ever heard of one person saying a VCM disabler made their car drive worse. Nearly universal is praise that it improves throttle response and driveability by elimination the momentary pause between stepping on the throttle and all 6 cylinders firing up. Team that with reduced wear and tear on the engine mounts and less stress on the transmission fluid and you have a LOT to gain with only 1 mpg or so to lose.
If you go with S-VCM or VCM Tuner II Advanced (which I would recommend) then you get a system that will shut itself off if the car starts to overheat for any reason, a valuable safety feature.
Only other downside is the fear that the dealer might see it installed and deny warranty coverage for some repair, although I've never heard of that happening here or on Ody Club forums.
If you go with S-VCM or VCM Tuner II Advanced (which I would recommend) then you get a system that will shut itself off if the car starts to overheat for any reason, a valuable safety feature.
Only other downside is the fear that the dealer might see it installed and deny warranty coverage for some repair, although I've never heard of that happening here or on Ody Club forums.
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