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VVCS De-Pin

30K views 89 replies 18 participants last post by  Dave2003  
#1 · (Edited)
Hello Folks!

After reading up on the issues for months, speaking to my techs "who are on board with me" I am wanting to remove the "smart charge" function from the VVCS.

Now I understand my friend @GreyFox has a thread about unplugging the VVCS from the Negative terminal. And I do know this does work.

I also know that @BLtheP has a GREAT thread on more info on this VVCS and the stupid function it serves for the .001 MPG it saves us.

My question is this, I want to de-pin the VVCS at the Negative terminal. Since the VVCS on the 2022 is new and it does other functions besides just telling the alternator to turn on or off, the de-pin route was explained to be the best.

I understand on the Armadas they were doing this to solve their voltage issues.

So, does anyone have the specs on the actual VVCS plug on the negative with the pin functions so I can push the wire out that way, still having the VVCS plugged into the negative.

Thank you

Happy Truckin'
 
#6 ·
I've been meaning to look into this for my 2020, but here's some stuff if it helps...

The connector at the terminal has a pin (#4) that monitors current, would it a matter of just removing that one?
Image


Here's how connector E161 relates to the rest of the charging system...
Image


Here's a visual of where E161 is the the fuse box....
Image


On the video, it talks about removing the pin at the ECM which following E161 to F78, it's on the other side of the engine...
Image
 
#7 ·
My question is this, I want to de-pin the VVCS at the Negative terminal. Since the VVCS on the 2022 is new and it does other functions besides just telling the alternator to turn on or off, the de-pin route was explained to be the best.

I understand on the Armadas they were doing this to solve their voltage issues.
Have we ever figured out what functions would be preserved by de-pinning, vs simply unplugging the connector @ the neg battery terminal on 2022's? I would think either is going to give stored trouble codes you'd only see with advanced scanners.

The system is kind of comical to watch on my 2022 S model with the silly graphical analog dummy gauges. The volt meter goes from 8 to 18V with 7 non labeled graduations in between.:unsure:

I've found that when cruising around town, which is very hilly, windy ~35-50mph travel for me, when you let off the throttle and coast down hill, the volt meter flings to the right, maybe 2 o'clock position. I'm assuming the VVCS throws the charging system into overdrive, using the alternator to help slow the vehicle.
 
#8 · (Edited)
I unplugged a few weeks ago with no issues what so ever. In fact it appears the windows move up and down a bit faster (not ever timed, just my observation). As far as codes, I checked for codes after one week and two week intervals and did not see any codes stored. I know several members in the 2nd gen group have eliminated the VVCS altogether and made their own negative cables to replace the VVCS without any issues as well. TruckinFLA even spoke with his local dealership techs who stated the VVCS is a nuisance and has been disconnected on previous other Nissan models when customers come in with electrical "gremlins".

This feature is like the auto-start/stop (A.S.S.) button in other makes/models. Many people have disconnected or bypassed those as well with no trouble codes. All these "fuel" saving features are more trouble that they are worth in my opinion and seem to cause more issues than save fuel.

My opinion is disconnect the feature only if you have a vehicle under warranty. Once your vehicle is out of warranty, I would make my own negative cable and eliminate the VVCS altogether. This way if you actually have an "electrical" warranty issue, you could easily plug it in to avoid the dealer giving you crap and possibly using THAT as an excuse to void the warranty ;)

EDIT: I purchased a digital an in cabin digital voltmeter to install a few weeks back, but have not had the opportunity to install it yet. The voltmeter gauge in my P4X is garbage and is not of use for me. Once I install the new meter, I can get a better feel of how the battery charging is going. But again, I feel the disconnect of the VVCS has only given me more confidence that the battery is getting a good charge all the time like batteries used to before these C.A.F.E. bull$h!T items came to be ;)
 
#9 ·
So I have had the VVCS unplugged for approx two months now. Weather here is getting cold/freezing and we had some snow a couple times. The truck starts and runs great. Remote start functions flawlessly, and I have not received any codes since the unplug. I did install a digital in cab voltmeter which has been giving me a pretty consistent 13.8 reading. Sometimes I see it drop to 13.7, and sometimes it goes up to 13.9, but I'm happy with it being consistent in that range all the time. The meter may be off or not that accurate, but it is showing no dramatic fluctuation, which was the point of the install.

That being said, I know some members have better knowledge of this than I do. Has anyone figured out the second more direct route in locating the correct color and location of the wire to cut/de-pin from the IPDM control module that carries the actual signal to the generator/alternator? I know there is documentation for the 2nd gen on this, but wanted to confirm for myself and others here if anything changed with the 3gen version. I do not own a 3gen service manual, so was hoping someone with one or knowledge could advise?? Thanks in advance. ;)
 
#10 ·
Have we determined if there is a difference between the 2022's VVCS system and the earlier systems?

All the youtube videos I've seen involve cutting a wire or depinning it from a connector. None of these videos show a pic of the connector at the negative battery terminal that you can unplug on a 2022+.
 
#11 ·
If it’s the same as my ‘21, and I’m betting it is, it’s got the current sensor on the ground cable just like Gen 2’s. I just unplugged mine on both my trucks.
 
#15 ·
A point I never asked and finally remembered to ask 🤪...
I'm am not sure if this "unplug" effects the battery saver feature of the vehicle (ie automatically shuts interior lights off if you forget to turn them off) since that feature is somewhat tied to the condition of the battery???
I would assume the black unplugged sensor on the battery terminal, that is mainly for the alternator, and has no effect on whatever "sensor" monitors the battery draining in general?? I could be totally wrong on this and am just asking and trying to verify. Anyone else with more knowledge please chime in and confirm or deny this for me and others. Thanks.
 
#17 ·
This may explain why one morning I went to get in the truck and the interior light was still on. It has only happened once and it was after I did the unplug. I'm not sure what I did to get it to do that though. I didn't think much of it at the time, now that you bring this up it makes me wonder. There could be something to that and might need some testing to figure out. I'd like to find the single wire to remove from the plug honestly.
 
#23 ·
I unplugged mine and thought my gas mileage went down after a 50 mile drive. May be a coincidence. I drove same route i always drive then filled up gas tank and thought i got 12 miles per gallon. 40 miles was freeway. 😳 Not possible for mpg to go down like that from unplugging vvc at ground cable. That same 50 miles i have gotten 18-19 mpg ???l😳😀.
 
#25 ·
The lie-o-meter on my 2022 rarely budges off "23.9 mpg average" fuel economy with my consistent highway usage (always ~21mpg when I calc it by hand) I gotta unplug this variable volt-O-later system and see if things change. If it wasn't 20degF out there right now I'd do it..
 
#27 ·
@Skibane had a good idea of locating a possible area for the de-pin:
2020 Frontier Battery / Charging / VVCS
Post #7 has picture

I attempted to locate and de-pin by process of elimination:
Image


Image


Below pic is rotated 90 degrees:
Image


Image



Front of connection slides out to reveal the front of pins and the little lock under them:
Image


Image



So it may be hard to see, but the top of the connection has a clip/lock that seems to lift ?? I tried to use a pin(picture) to popthe little locking tab in front, but the pin still wouldn't move. Not sure if that top tab/lock needs to be opened more? It was cold out and I hardly had time during my lunch break to get any farther. I didn't want to risk breaking the connector.
Image



Anyone know a better way to de-pin? Once I am able to de-pin, I plan to go through each wire until I see which one is the correct pin/wire color.

@Skibane, you still around? You seemed to have a great grasp of this VVCS and the actual wire to de-pin?? Care to share any additional info or tips??
 
#29 ·
@Skibane had a good idea of locating a possible area for the de-pin:
2020 Frontier Battery / Charging / VVCS
Post #7 has picture

I attempted to locate and de-pin by process of elimination:
View attachment 361837

View attachment 361838

Below pic is rotated 90 degrees:
View attachment 361839

View attachment 361840


Front of connection slides out to reveal the front of pins and the little lock under them:
View attachment 361841

View attachment 361842


So it may be hard to see, but the top of the connection has a clip/lock that seems to lift ?? I tried to use a pin(picture) to popthe little locking tab in front, but the pin still wouldn't move. Not sure if that top tab/lock needs to be opened more? It was cold out and I hardly had time during my lunch break to get any farther. I didn't want to risk breaking the connector.
View attachment 361843


Anyone know a better way to de-pin? Once I am able to de-pin, I plan to go through each wire until I see which one is the correct pin/wire color.

@Skibane, you still around? You seemed to have a great grasp of this VVCS and the actual wire to de-pin?? Care to share any additional info or tips??
I still can't wrap my head around any of this, but I have a silly question. Why try to find the cable at the IPDM when you can just cut the wire at the terminal? If the goal is to prevent the VVCS signal to reach the alternator, isn't it easier to cut or depin at the negative terminal?
 
#35 · (Edited)
Again...lots of 2nd gen info regarding the VVCS, just trying to iron out the info and discrepancies for the 3rd gen. ;)


Battery Voltage at idle?

2020 Frontier Battery / Charging / VVCS


Someone mentioned disconnecting the one wire from the alternator itself...:unsure:
This may be even easier than putzing with pins in the fuse box. Should only be one thin VVCS wire to the alternator?? When the weather gets warmer and cleaner out, I'll have to investigate this unless someone else beats me to it here :D;)
 
#36 ·
Again...lots of 2nd gen info regarding the VVCS, just trying to iron out the info and discrepancies for the 3rd gen. ;)


Battery Voltage at idle?

2020 Frontier Battery / Charging / VVCS


Someone mentioned disconnecting the one wire from the alternator itself...:unsure:
This may be even easier than putzing with pins in the fuse box. Should only be one thin VVCS wire to the alternator?? When the weather gets warmer and cleaner out, I'll have to investigate this unless someone else beats me to it here :D;)
I have been wanted a dual battery set up for some time, and while I know the isolators are fairly inexpensive, I have been seriously considering a DC to DC charger which significantly adds to the cost, but would directly fix the charger problem. They specifically recommend DC to DC chargers in general to any vehicle with a smart alternator to solve charging issues. No need to cut or unplug anything with such a set up.
 
#42 ·
@estunum
Thanks for posting all this valuable information. While some may not care, notice, or appreciate the info and effort...I do (y)
Thanks ;)
Haha of course! I’m no expert but try to find the answer to things because I may run across it one day. This whole VVCS thing is interesting for sure. I’m actually driving right now as passenger in my truck and voltage has lived between 12,5 and 12.8 the last 30 minutes. Have seen it dip as low as 12.2

Image
 
#48 · (Edited)
Upon further digging, it seems that for 2023, there might be 2 possible methods to disable VVCS. Personally, it seems like #2 would be the best solution, as that is only sending a PWM signal TO the alternator, and is a lone single wire; and hopefully the least/no chance of throwing error codes.

#1 - Depin/disconnect (PIN 4) the battery sensor to ecm connection. See image.



#2 - Remove the connection between ECM and alternator. According to the manual, in the absence of the PWM signal, "the generator/alternator performs the normal power operation" See images below.





 
#51 ·
Couple of points in confusion here.

Ipdm is not used in this charging system 2020 and newer.

Pwm signal is only from ipdm to alternator, and only 2019 and older.

Removing pwm signal is how the pre 2020's were disabling the vvcs.

The 2020 and above use lin bus to communicate between ecm and alternator. It will trip an error to remove this connection.

2020 and above will also store codes without a mil lamp if you disable the current sensor.

There is no information on how the 2020 and above alternator will work without ecu communication over the lin bus.

The 2019 and older would go into the default voltage control like the old dumb alternators when it did not get the pwm signal from the ipdm.
 
#53 · (Edited)
According to schematics, it appears to be LIN.

Image


So my question would be if one disconnects the LIN from the alternator, no MIL is indicated on dash (which is fine), but it does throw a code?? Is that a code that only Nissan/Consult will read or is this a PCM/OBD type code that will cause for concern? Also, will the alternator go into "dumb" mode and just provide full charge?

I would think Nissan has a work around for this, especially for the customers that travel less than 8 miles per day where the charging system does not fully charge the batteries. Techs disabled the VVCS for these certain customers in the past, so there should still be a way of doing this on the newer vehicle's ???

Excuse me if I'm repeating things...I'm jumping back and fourth between two threads on CF about this, and the Nicoclub forum about the same issue :p
 
#57 ·
This "voltage divider circuit"...what does that entail? :unsure:

Also update from Nico Club forum:

"It isn't something we've come up against with D41's yet, although it's been very common on '17-up Armadas. I really don't see any reason not to snip the Pink sensor wire, which should simply force the ECM to regulate using voltage like a conventional regulator. So it should have the same effect as snipping the wire on a PWM setup, with the exception that you'll get a P155x code. You'll know why that's there, so I'd say just ignore it."
 
#58 ·
Looking at the error codes, the ecm expects from the battery current sensor a voltage above.22v and below 5.06v on the battery current sense line (E161pin 4).

You need to provide the correct voltage for max charge between those 2 values (not sure without testing) back to the ecu on the wire from pin 4. To get the voltage correct it's possible to use 2 resistors one each run from the 5v and the ground on E161 such that the middle point between the 2 resistors is the voltage you want.

This is in simple terms in practice it is a little more complex. For example if the resistors are to small in value you could smoke the ecu or burn up the resistors.

 
#59 ·
Interesting, but a little too complex for me. I haven't done Calculus for many years :ROFLMAO: I'll stick to cutting the pink wire route at this stage in my research. I would prefer to de-pin the wire if I could figure out that stupid plugs locking mechanism?? I was able to slide the white locking part "partially out". Not sure if it is meant to come out all the way, be a one time locking piece, or what? I may just go few inches down the wire loom line and snip it down there and put two connectors on the ends should I ever need to visit the dealer and need to have it reconnected? Still debating.

@JVRaley, how has the charging and voltage readings been since you did the snip? Everything seem to be running ok and getting a better charge? I know you mentioned you were adding a second battery to the bed.
 
#62 ·
maybe try finding a 12v car wiring group on facebook and ask. There's some that are dedicated to racecar stuff and work with all kinds of plugs and pins, so they may have some insight on how to depin it. Also, I wonder if there is any place you can get a male and female plug to make a short extender, which you could leave that single wire out, rather than cutting the harness
 
#64 ·
Actually I just had another thought. would it be possible to put some kapton tape over the pin to isolate the signal? that might work and not be a permanent modification. People use it to block pins on sata connectors on pc hard drives to kill the 3.3v signal when they shuck disks out of usb enclosures

Both are good options, I just don't think access to apply the tape would be feasible. If one could de-pin to gain access, might as well just leave the pin out vs. taping it and reinstalling? IMO

I also like the extension idea, might have to see from Nissan what part number that is? Although my luck with the parts counter staff is atrocious (try asking them to find the OEM engine block heater for the Frontier and see the glazed look they give you back o_O:oops::ROFLMAO:)

I'm pretty good at figuring stuff out on my own. I will try this "locking" connector again before I submit to cutting. It's personal now :mad::LOL:

Appreciate the ideas though. Maybe another member here will find a better option or use one of your ideas ;)