vF Tuner for the 3.5L Tacoma-AGM tuning

Here is the updated voltage tables based on the 14.4v optimum, as well as the 13.2v floor, which I set to 13.3v for a fudge factor.

Additionally, I believe the maximum mechanical output of the stock alternator is 14.8v (Possibly 14.7v, getting conflicting answers), so anything above that is going to max at 14.7v or 14.8v regardless of what values are set.

Temp (C) | Voltage
-----------------
-40 | 15.57v
-30 | 15.39v
0 |14.85v
30 | 14.31v
60 | 13.77v
90 | 13.3v
120 | 13.3v
150 | 13.3v
168 | 13.3v

 

is -30 and -40 the values you replaced that big 65496 and other # with?

 

Yes, those are the signed values of those numbers.

I'm going over the numbers and wanted to point out since the alternator has a max mechanical output of 14.8v (or 14.7v), there's probably no harm in overshooting your numbers if you're looking to get max voltage, but there IS harm in going too low, as it will potentially wreck your AGM battery if you try to charge it with anything less than 13.2v for any significant period of time. That said, if your engine bay is exceptionally hot, overshooting could cause harm as well... but with the cold weather approaching, I'd bet it's safer than undershooting at the moment.

As a secondary side note:

I did accidentally flash without updating the Base Phase Duty table, and only updated the individual duty boxes. My output voltage didn't change... so it would seem that the only thing affecting the output was the duty table (the one with the colored boxes) ... which brings up many more questions.

 

can you take a screenshot of the table with your values please (when you can)?

 

Yep, here you go. I just updated my tables to reflect what I think will be proper voltages based on temp. I haven't been able to test them other than at idle though, but ambient is about 15C, and voltage at the battery terminals is right at about 14.28v. I suspect engine bay temp is reading higher than ambient though, so that tracks with the slightly higher than desired voltage based on ambient.

I'll need to drive it tomorrow to see if voltage drops/raises accordingly. Also, my engine was warm by the time I zeroed in on these numbers, so a cold start in the morning should give me more data to work with.

60 and 90 are just a best guess though. 120-168 are also best guess at keeping it above 13.2v, but there's probably some room to play with in there.

I suspect my Base Phase Duty numbers would shift if my Duty cycles were stock, but since I altered them already based on @banjoist13 , I just left them alone and I'm trying to adjust the output only with the Base table, which seems to be working.

This is for my 2017 04B04 ECU, so your results may vary.

 

I just flashed using @banjoist13 values. Start up at 14.5, held 14.3 while driving around...did seem to drop to 13.8 once at a light. Other than that for my first time using vFtuner I call it a win. Thanks for the great advice and information!

 

It should not be dropp

www.northstarbattery.com/faq?redirected=true
So instead we have set charging the charging parameters of between 14.1 volts and 14.8 volts as an acceptable charging range. So long as the battery charging remains within these tolerances the battery will perform to its engineered specifications. This is for group 31 Northstar.

 

It dropped for 1 second and never did it again...will keep an eye on it. I was using the voltage gauge on my USB port

 

Yeah, that's an acceptable charging range within certain temperature limits. But after speaking to Northstar directly, that FAQ doesn't cover the reality of an engine bay. So while you'll probably be ok with that, it's not optimum. Why not make it optimum, since we can.

It was very explicitly stated that charge voltage should drop as temperature increases, but no lower than 13.2v. In really hot temperatures, I'm pretty sure you don't want to be jamming 14.5v into the battery at 100C until it cools down.

My cigarette voltage reads 0.2v lower than battery at the terminal. Just FYI. Yours may differ, though.

 

I have a 18 model has anyone had a good result with their numbers. Trying to have the guy that did my tune. Flash it again because at 95 when we first flashed. It would throw Check charging but as soon as i would drive it would go away. Now after a Week of the truck sitting. I see it stay at 14.4 while i drive but as soon as i stop it jumps down to 13.3 then back up as soon as i go again.

 

Base phase duty is what changes the voltages. The individual duty tables need increased to get to those higher voltages.

If you just increase base phase duty, you’ll have to go higher, or wont get the numbers you want.

 

Same exact issue on my 18. I tried the “bump everything up 20%” method, and didn’t get proper results.

 

Have u tried this thats one recommendation i got wondering if that will work. On our 18s my tune guy lives Far so i havent gone back to do this.

 

I said the same thing but ignorance is bliss with people lol...


https://www.tacomaworld.com/threads...tacoma-agm-tuning.689652/page-3#post-24395768

 

i think the issue is that nobody is exactly clear on how the vF column data is applied in the real world. you kind of said it yourself... we're waiting on actual info. or you could call it ignorance if you insist.

 

Can AGM batteries charging profiles also differ between battery makes and models?

At one point earlier in the year I asked Odyssey about throwing a constant 14.7 volts at my 2x g35 pc1400s and this is what they said:

"14.7 volts is where the Odyssey battery loves to be.

Your alternator will cut back amps as the battery gets to be 100% charged, so no chance of over-charging …"

I haven't dug into temp stuff yet

 

Its either or, depending on the person...Im half and half

 

Forgive me if this has been covered, but can I assume that this has not been sorted for the 2020 trucks ECU's yet? I've seen some posts that the 2018 and up have some different pids?

Thanks,

John

 

I believe its working on 2018-2020. I’ve personally done it on a 16/17/19 so far.

 

Would u share the Number u did on the 19. I have a 18 and have been having issues. Im getting the Check Charging System Continuously at Different times. Either slowing down or running the truck for a while then turning off the truck then back on i get the Light.
Thanks