johnnyytruong

jjrphs

Not much to say except the S-VCM Controller installed in my wife's RDX still works as advertised.

auskip07

I do get lesser MPG in the city but my Highway mpg is about the same at 70mph im getting around 27mpg from Atlanta to Auburn about 120 miles. I did 70-85 on my way back and it got down to 23 mpg

Acc20yrs

Running mine since May 2018 on a 2014 RDX Tech without any issues. It took care of that nasty VCM vibration. Enjoy!

johnnyytruong

Comfy

Acc20yrs

Update: I've been running S-VCM since May 2018 without any problems. All vibration is gone, fuel economy is about the same. Throttle response seems to have improved a bit. So far, it is worth every penny.

wsw

I've been running the S-VCM since March 5, 2019 and have put a little over 1,000 miles on it. The RDX AWD Advance runs fine on it and I like running on six cylinders full time. However, the RDX has the random, intermittent "hesitation" upon acceleration from a stopped position. The S-VCM did not eliminate the "hesitation" situation by itself. So, today I had the Valvoline MaxLife ATF installed in the transmission at a drive-thru Valvoline Instant Oil Change store. Total cost was $159.99 including tax and the transmission held 18 pints of ATF. The transmission and lines were emptied and fluid replaced by a suction machine. The mileage on the RDX was 37,451 mi. at the fluid change.

I drove home for a distance of about 15 miles, through a mixture of city (stop and go traffic) and freeway traffic. So far there were no hesitations in acceleration from a stopped position and the transmission performed smoothly and very responsively. I will monitor it for the hesitations and report the results back here.

As a side note, the transmission fluid had been changed as part of CPO reconditioning by the dealer that I bought the car from about 2,000 miles ago. The dealer had used the ATF DW-1 fluid. In the interest of getting the "hesitation" solved now, I opted to dump the brand new DW-1 ATF fluid in favor of the Valvoline MaxLife ATF.

jjrphs

I agree with everything in your post with one exception...please don't do not do another ATF service with a flush/exchange machine. DIY or have a trusted mechanic perform ATF drain and fills. Mechanics like the flush/exchangers because they're quick,easy and high profit...I've always been under the impression they're not good for Honda transmissions.

As an aside...I just picked up a cherry 2012 TL-BASE with 50k miles and I'll be performing my standard 3x drain/fill with MaxLife in the next couple days.

Thanks for the post and here's to good luck in your RDX driving and performing as it should.

SpencerD

I’m curious how this will affect the radiator fan operations. For instance, if vehicle is parked with engine idling, the fan will be activated from time to time to cool down the engine by circulating the coolant through the system without the S-VCM. With the S-VCM installed, since the ECU is now tricked to believe that normal operational temperature has not reached, it will not activate the fan until the engine has reached an internal temperature of 230F or higher. So in this case both the coolant and transmission fluid are hotter than normal. Does anyone see a problem here from a long-term perspective? I’ve read all the FAQs on the S-VCM site but haven’t seen any description related to my concerns above.

mbJax

I can't provide a technical response, but I installed the s-vcm a few months ago, and my radiator fan is very active. Engages after very brief idle periods (in Florida heat with a/c running), and kicks in and out often. It does worry me not seeing accurate temp readings, but my fan is definitely not disabled by the s-vcm.

jjrphs

Like other Hondas / Acuras, the 2nd GEN RDX has 2 temp sensors...A & B. Temp sensor A information is the reading which S-VCM Controller "massages" and sends to the ECU. From my understanding...Temp Sensor A reading of ~200*F will trigger the fan switch and Temp Sensor B reading of ~220*F will trigger the fan switch. So, if S-VCM Controller keeps the ECM "tricked," the radiator fan will still kick on ~220*F. Either temp is well above normal operating coolant temp and at the upper end of what you'd want your ATF temp to be in continuous operation...transient temps of >200*F with the vehicle under heavy load would probably be OK.

Having said that, another member's OBDii data indicates the normal operating coolant temp is ~175*F...well under the temps which triggers the fan anyway. So to me it is questionable as to whether coolant temp in the radiator would ever reach the temps you're concerned about under normal conditions.

Finally, all Hondas / Acuras turn both the radiator and condenser fans on when the AC switch is engaged...which is pretty much continuously in my case and I'm sure most others. As a practical consideration...this more than anything else would prevent coolant (or ATF) temps from reaching and staying in the upper end of what is safe.

This is my understanding...if I'm incorrect, someone with a better working / technical knowledge will chime in.

SpencerD

I'm going to install the device and let the engine idle without A/C running to see if the fan will activate. If it does near the normal temperature range I should have no worries. By the way, it seems the seller now ships from the New England region in the US. I received it slightly over a week later after ordering from the site, paid less than $5 in shipping to Maryland.

jjrphs

Before you do that (install and test)...run the vehicle now without the AC engaged to see if you can get the radiator fan to come on by itself. That way you have a baseline comparison.

I will say that with all the Hondas / Acuras I currently own and have owned...I rarely note the radiator fan coming on by itself (without AC engaged). I believe my Element will do that occasionally but that's either after pulling our jet-ski, been after driving some time, when the ambient temp has been high and the car sits a few minutes while running.

HTH

egads

Always install a VCM deactivation device with the engine cold. Installing one on a warm engine will set a check engine light. Now that light will go out after a few cycles, but if one is
installing and giving the car back to the spouse...

Tech

One way to find out is to get the specifications of the temperature sensors; maybe they are both the same. They usually have a resistance that varies with temperature and that is the chart you need. They might be an NTC type (Negative Temperature Coefficient), whatever.

Then hook up a decade resistance box to where the wiring is hooked up to the sensor and set the resistance to something around the 160F mark and work your way up to the 220F mark and note when the fans turn on. This will work if only the coolant sensors are looked at and there is no other sensor that enables the circuit.

egads

I just looked at some threads at the Odyclub about the activation of the cooling fans. They do work like jjrphs says.
For future reference around here: The S-VCM can be ordered with additional wiring to allow a switch to be installed to shut it off.
(for either better fuel economy when cruising or for reporting real temps when servicing)
There is also available a product called VCMTunerII that works just like the S-VCM except that
it automatically shuts itself off if the engine reaches a high temp (and that will show on the dash gauge) It also reports the real temps to the ECM
when the engine idles. Many Honda repairs & maintenance require an "idle relearn procedure" to be done, that makes that easy.

By the way, I have been a long time member over at the Odyclub where Maxlife trans fluid has been the choice for the transmissions mated to the Honda V-6.
I can assure you that those vans see a far more extreme service than a light weight RDX. But the most important thing anyone new to Honda automatics needs to know
is that regular trans fluid changes are required. A normal drain & fill every other oil change is not too much. That includes using Maxlife instead.

SpencerD

Well, I tested with and without the S-VCM (A/C turned off), the fan would kick in periodically in both cases. So those observations confirmed there were no interruptions to the fan operation. For now I will leave it connected. I also used an OBDII scanner (about 10 years old) with live data display but unfortunately the tool only showed a reading of 165 F for ECT (engine coolant temperature). Obviously that value was already altered by the S-VCM. Not sure if there are more advanced scanners which provide readings from both temperature sensors or maybe the vehicle's ECU only gives that single value.

Tech

Well it would be interesting to know at what ACTUAL temperatures the fans turn on and off at with and without the S-VCM. I am sure that would be listed in the factory repair manual, at least for the stock version.

So far, lots of guessing going on.

egads

What difference does it make? They work, with or without a Muzzler device. Perhaps the best solution here is to take OCD medication.

jjrphs

Unless I'm mistaken, SpencerD got the answer he was looking for. Regardless, it seems you're the only one requesting the information above and beyond...is there a reason you (being retired and all) can't let your fingers do the walking and answer your own question(s)? Then let us all know what you find? I'll stand corrected on Temp Sensor A reading of ~200*F and Temp Sensor B reading of ~220*F triggering the fan switch respectively if that is incorrect.

Tech

I take it those numbers are out of the Acura shop or repair manual...or?

jjrphs

Tech

I'm going to have to download the rest of the manual or whatever I can on a day subscription. So far all I got was the maintenance section.
Its summer, so I'll wait till I am stuck in the house due to bad weather.

Would you happen to know how many pages there are?
And what is the best way to save the info? I think all I did was print the Maintenance Section out.
dave08902 posts his in PDF format.

Fterrazas01

Evening gentleman, sorry but you have a newbie on your hands. Not even sure if I'm posting correctly. Just purchased a 2013 RDX w/Tech. Totally excited. Love the car!!!! Have been reading on the VCM fix and just finished ordering the S-VCM controller. Will also be following with changing to Valvoline ML on the tranny. Thanks for everyone's great comments. In all that I've been reading lately not sure if I've come across anything on what I'm about to ask. I'm not by any stretch of the imagination a mechanic but can get around cars well enough. So here's my question. By making the mod and now utilizing all 6 cylinders at all times is there any possibility of now increasing the towing capacity from 1500lbs to 3500lbs? Sorry for such a novice question. But can this be done or should I not even think about. Thanks for any responses and everyone's thoughts.

egads

I think the towing capacity is based largely on the mass of the vehicle more than its power.

Poolman

The towing capacity is limited by the strength of the rear suspension. Acura says it will handle 1500 pounds,,you can bet it will handle just that. Hook up 3500 and you could cause some severe damage to the suspension parts. The engine and drive train would handle it,,my sons MDX pulls his camper with no sweat, but he has the suspension to handle the weight. Same engine and trans as my RDX, but I wouldn't dream of trying to pull my camper with it..That's what our Sequoia is for.

Fterrazas01

Thank you. Won't be doing it.

Poolman

After a couple of years with the S-VCM hooked up , I had been noticing something peculiar. While driving down the road I had noticed that the trans felt like it was going into lower gears while at speed when letting off the gas , on long down hill straights a 60 mph. Yesterday I was looking around under the hood , to see where one might add an oil catch can. I noticed that the hot wire from the S-VCM was severed , thus discontenting the device. I at this time am not sure if the wire was burnt through or if it was possibly severed by mistake when I had a replacement battery installed,,but in any case I though to ask here on
the forum if any others had this problem arise.

jjrphs

My S-VCM continues to work as advertised and the wife's 2013 RDX is still the refined, powerful driving experience it should be. I don't drive it all that much myself...just on trips and when I service it.

The power wire for the S-VCM shouldn't be routed around anything hot enough to burn it in two...so it was probably cut when your battery was replaced. I don't know what gauge the wire is...but it is small. I like the "solder seal wire connectors" for such repairs / splicing. All that is required is a heat gun...they work as advertised in my experience with cars, motorcycles or boats.



Good luck and I hope you get to running on all 6 cylinders, all the time, very soon.

Poolman

Oh , should have added, it wire was soldered and then covered with heat shrink and fixed. Yep 6 cylinders all the time again.

egads

The guy who sells the VCMTunerII includes some velcro tape to make sure wires are held out of the way. I installed a used one and had some because it is so handy around desks and audio equipment to
keep wires neat. Better than zip ties when you need to redo and relocate.

JazhielS

I just bought a 2014 rdx, runs awesome, the only issue is the rough down shift btween 2nd and 1rst gear. Last night i read all the post in this thread wich made me think why the engine is so beautiful clean on the car i bought. It almost looks brand new and i think is because it actually is. The dealer gave a 1 year warranty on whole transmition and engine. It looks like the previous owner dint took care of that vcm and ended up blowing either the engine or trans. So my guess is thats the reason for the cleanness and warranty on them. As for the maxlife i am thinking about it

egads

"The dealer" means an actual Acura dealer? How many miles (or km) on it?

Reading through this this whole thread again, I should also add: there is a service bulletin on the six speed transmissions
that includes a software update. (They also do a 3x fluid change)

http://www.urvi.net/forumfiles/SB/B17-017.PDF

There is a subsequent one where they do an additional full fluid change for folks still experiencing symptoms. There is also a warranty extension to 8 years/80k.
The bulletin also lays out the right way to do a full fluid replacement. Included is the warning to never use a fluid replacement machine on a Honda/Acura transmission. They do the change completely on the rack, but if DYI, you could just do fluid replacements each weekend. For three weeks. The driving in between needs to be more than just around the block. You have to go through all the gears and have the torque converter lock up.

JazhielS

Its got 73600 miles, it wasnt at an acura dealer, it was a buy "as is". So about that bulletin, is that like a recall kind of thing r how does that work. My next imediate move will be replacing the vcm and see if it improves driveability. If not, ill do the trans drain. That one looks brand new fluid so ill probably try maxlife

JazhielS

Its got 73600 miles, it wasnt at an acura dealer, it was a buy "as is". So about that bulletin, is that like a recall kind of thing r how does that work. My next imediate move will be replacing the vcm and see if it improves driveability. If not, ill do the trans drain. That one looks brand new fluid so ill probably try maxlife

egads

I would not assume the engine/trans is new just because it is very clean. Modern engines do not get that dirty. Almost all used vehicle get their engine compartments cleaned along with the usual detailing.
A one year drive train warranty is pretty standard. How does a service bulletin work? They are not recalls. They help dealers correct owner's problems, especially with know issues. I think having the software updated
is worth it. It keeps the fluid from breaking down fast. The RDX taxes this transmission the least of any vehicle Honda uses it in (well maybe the V6 Accord also) There is no magic to using Maxlife fluid. It is just
much cheaper and very available for folks who like to keep the fluid clean. To get an Acura dealer to do the service bulletin, one would have to say you were experiencing a "judder" during shifts. that is a sort of slipping feel while changing gears. I mostly noticed it when going up hills under light throttle.

One does not "replace" the VCM, one muzzles it. All the devices trick the engine management system into thinking the coolant is not quite warmed up enough to allow the cylinders to shut down.

JazhielS

Thanks for all the info..so i decided to get the vcm..only am not sure wich one to get..i think there are couple versions out there..maybe the muzzler would work for the rdx, idk, wich one and where to buy it from would you recomend..i clickd on the link at the beginning of the thread and tried contancting the guys by mail. But its been 24 hrs and no answer from them so i just dont wannna risk loosing my money..also i dnt really like buying mechanical car parts from ebay..

Alex Medeiros

I'm pretty sure this is the correct one.

https://www.vcmtuner.com/products/vc...e-vcm-eco-mode

wsw

Or this one: S-VCM Controller