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Discussion Starter #1
So, I don't want to hook it up to the AC wire. I mean, yeah. I could hook up a switch or make a connector so that only one or the other can be hooked up at one time, but I know you can go through the EGR valve too, but I a cannot find anything on either where the **** wiring is for it, nor if our cars even have one. Lol. I figure if we don't have one, I can pin the signal wire from my AEM wideband to the ECM directly and also not ever risk breaking anything if, say, I forgot to flip the switch back or something stupid like that (I toke. Sue me. ;) lol).

So, can anyone show me one of the follow please? Yes, I have searched. Just haven't come up with anything definitive. I do have a manual (haynes), but they are garbage nowadays (they used to be much more detailed), and on top of that, my dog literally chewed it up. Not even kidding...

I need any or all of these for 2015 LUV MT e78:
  • PCM pinout
  • Wire color/location of EGR pintle position sensor
  • wire color/location of AC pressure sensor (just in case I find not other options)
  • ANY other non-critical component that sends a 5v signal to the PCM to tap in to
  • ANY option whatsoever
  • breakfast (never hurts to ask)
  • Advice on using a UART to USB chip to serve it in by itself (via the serial wire that comes with it. It should work. Just haven't tried and I have a dozen UARTs).
Thanks. Really hoping to get an answer soon. People don't tend to respond when I ask in the forums. Not entirely sure why. It would be greatly appreciated though.
 

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Discussion Starter #2
welp, looks like it is either one of these pins. 50, 51, 52, or 55. I am going to look and see which ones are not used and update shortly
 

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People don't tend to respond when I ask in the forums. Not entirely sure why. It would be greatly appreciated though.
That's because your blazing a new trail.

For the diagrams, try to see if your local library has a subscription to AllData or something similar and just download the diagrams.
 

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Just use a gauge.


The way I would do it is just have a little box send it over the can and then you can just grab it over obd2 like anything else. But this is really expensive to do and I doubt hp tuners supports anything like that.

Or even just stream it over Bluetooth. Why even bother with wires?
 

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Discussion Starter #5
I checked alldata and I found nothing. I have a friend that works at a stealership, and he is trying to get some info. From what I am seeing, pin 9 seems to be the unused, most likely winner for all of us. I will take a volt meter to it tomorrow and see if that is the case.

As for sending it over the can, I am NOT spending HELLA dough on a simple signal translator thingamabob. F*** that.

"The way I would do it is just have a little box send it over the can and then you can just grab it over obd2 like anything else. "

Hmmm. What little box? How would you build it? MCU, SoC? I am an engineer and can for sure make one. I almost went the route of building something out of a UART and an arduino... But not everyone can do that. My findings for hooking this thing up EASILY, are the following:

a) A/C Pressure Sensor (short tutorial coming soon. This is what I did)
b) EGR pin on PCM (I have yet to find it, but any unused 5v PCM input should work. That was my actual goal; to integrate it in properly. Alas,will take more research)
c) Fuel Tank Pressure Sensor (I almost did this, but it was easier to get to the A/C Sensor wire. Like, MUCH easier.
 

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Discussion Starter #6
So apparently the ac wire will not work. I only get between .200 and . 1.200 or so volts reading from my wideband into hp tuners. Though from what I understand the p03 position on my gauge allows it to read in that range and though the forums disagree here and there it looks like the resolution is something workable for us. I'll do a writeup on it soon. I want it to be something yiu can do with what you already have and not have to buy serial cables (which is likely the best, cheapest solution.).

And I so have an arduino and lots of random computer parts. I may do a writeup on too.
 

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Discussion Starter #7
Just use a gauge.


The way I would do it is just have a little box send it over the can and then you can just grab it over obd2 like anything else. But this is really expensive to do and I doubt hp tuners supports anything like that.

Or even just stream it over Bluetooth. Why even bother with wires?
Yes making can box would work, but you would have to transform the serial adapter anyway so may as well go the serial route. And I do use the Bluetooth option for logging but you can only log what comes through the obd2 port, hence the desire to utilize existing wiring (the fuel tank pressure sensor may be an option too. It's just to know when to set the purge for it on and off from what I know.). I will always use a wire for flashing though. I work with electronics/computers for a living and don't trust that the incumbent device will not get bricked if bt takes a sh**.
 

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I checked alldata and I found nothing. I have a friend that works at a stealership, and he is trying to get some info. From what I am seeing, pin 9 seems to be the unused, most likely winner for all of us. I will take a volt meter to it tomorrow and see if that is the case.

As for sending it over the can, I am NOT spending HELLA dough on a simple signal translator thingamabob. F*** that.

"The way I would do it is just have a little box send it over the can and then you can just grab it over obd2 like anything else. "

Hmmm. What little box? How would you build it? MCU, SoC? I am an engineer and can for sure make one. I almost went the route of building something out of a UART and an arduino... But not everyone can do that. My findings for hooking this thing up EASILY, are the following:

a) A/C Pressure Sensor (short tutorial coming soon. This is what I did)
b) EGR pin on PCM (I have yet to find it, but any unused 5v PCM input should work. That was my actual goal; to integrate it in properly. Alas,will take more research)
c) Fuel Tank Pressure Sensor (I almost did this, but it was easier to get to the A/C Sensor wire. Like, MUCH easier.
It’s a small box with custom built and everything. It’s ESP32 based like our obd2 adapter.

But sadly low volume and I can’t imagine there being much demand for such a thing. That makes it really expensive.

It’s really unfortunate cause there isn’t really an arduino for cars. Sure you can make one but it just doesn’t have the reliability. One alternator dump and ZAP.
 

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It’s a small box with custom built and everything. It’s ESP32 based like our obd2 adapter.

But sadly low volume and I can’t imagine there being much demand for such a thing. That makes it really expensive.

It’s really unfortunate cause there isn’t really an arduino for cars. Sure you can make one but it just doesn’t have the reliability. One alternator dump and ZAP.
Couldn't you use a battery as a buffer, similar to a laptop?
 

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Discussion Starter #10
Serial by far the easiest cheapest way to do it. I did a write up here: https://www.cruzetalk.com/threads/howto-aem-hp-tuners-cruzin-together-vve-tuning-with-aem-wideband-and-hp-tuners.245324/#post-3256129

Cost less than 20 bucks, no offsets to worry about, and I had it set up and going in less than 30 minutes. Now the problem I'm having is my **** wideband, after the car I'd warmed up, it reads full lean, and I know that is not the case. Unless there is some table in hp tuners that is making my car run full lean after its warned up. I notice too that when it does this if I turn off the power to the car (key off and out, open and close door) then start it again, it read normal again for a few minutes then does the same thing. Any tips?
 

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Couldn't you use a battery as a buffer, similar to a laptop?
You would still need to protect the battery from the car. as it is just as vulnerable if not more. Plus any input needs to be protected.

Batteries aren’t reliable for this style anyway. For a few uses here and there it’s fine but when you have 100s of the things running it’s important to make sure they never fail. just look at dash cams.
 

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Doesn't matter because serial is easier and cheaper. ;)
I cannot comment on that as it is above me at the moment. I have been out of electronics and programming long enough to be dangerous.

You would still need to protect the battery from the car. as it is just as vulnerable if not more. Plus any input needs to be protected.

Batteries aren’t reliable for this style anyway. For a few uses here and there it’s fine but when you have 100s of the things running it’s important to make sure they never fail. just look at dash cams.
I am not sure I follow your logic. I deal with larger UPS's and invertor's, but the laptop is still a good example. With it plugged in getting a continuous charge, there is no issue with spikes and such as the battery absorbs them while giving the computer a continuous flow of relatively clean power. Now I understand if the house gets hit by lightning all bets are off, but you'll have to live with that risk or figure out how to use an MOV in the circuit.
 

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I am not sure I follow your logic. I deal with larger UPS's and invertor's, but the laptop is still a good example. With it plugged in getting a continuous charge, there is no issue with spikes and such as the battery absorbs them while giving the computer a continuous flow of relatively clean power. Now I understand if the house gets hit by lightning all bets are off, but you'll have to live with that risk or figure out how to use an MOV in the circuit.
That logic is only true if the battery is basically large enough to dwarf any spikes, such as is the case with a car battery.

Optimally the car battery absorbs any sharp rises in current such as from the alternator. But if that fails the current generally doesn't disappear which will then cause a voltage spike. A small li ion battery just can't handle it. Considering a vehicles power system is fairly large and sprawled out, this happens more than we'd like.

Batteries for small electronics such as a laptop are generally in the 2V to 4V range which also makes things complicated when you want to charge it with 12V. as that is all additional circuitry which needs to be exposed to the 12V side.
 
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