DIY MS3 V3-board jumper questions
 

I searched through every thread and resource in order to answer my questions, but they all come up short as far as my specific setup. (pls no bully)
The most helpful pages were these:

https://www.miataturbo.net/useful-sa...asquirt-13676/

https://www.diyautotune.com/support/...rt-your-miata/

Now as to some background of what I am struggling with. I bought this MS3 kit 2 years ago without a whole lot of research. I would have gone PNP if I had known better.

https://www.diyautotune.com/product/...th-black-case/

I currently have a 97 that I am planning to turbo in a few months once I gather enough parts. I'm going to build and install the megasquirt system before I do this in order to get familiar with it, something you guys suggested.

I am confused as to what jumpers and mods I will need to perform on this board. It is my understanding that any V3 board, whether it be MS1, MS2, or MS3, aside from the MS3X (which this isn't right?), needs the same jumper job performed. Correct me if i'm wrong.

I am planning to run the wasted spark FAB9 COP system. I won't bother with sequential ignition for now unless that somehow saves me from having to do some of these mods to the board.
I am planning to run sequential injection.
I will not be keeping the stock ECU, only the harness-side connector.
Won't be running AC (for now).
Mechanical boost control.
Planning on running a UEGO wideband.

If you guys could point me to the right setup for modifying this board, it would be much appreciated. I'm in over my head and feel stupid for having to make a thread. Forgive me, but i'm at my wits end right now.

https://cimg5.ibsrv.net/gimg/www.mia...e300bbdecd.jpg
https://cimg6.ibsrv.net/gimg/www.mia...abcddaf729.jpg
https://cimg7.ibsrv.net/gimg/www.mia...005178175f.jpg
https://cimg8.ibsrv.net/gimg/www.mia...3291e4856a.jpg
https://cimg9.ibsrv.net/gimg/www.mia...1eefe916b2.jpg
https://cimg0.ibsrv.net/gimg/www.mia...a571529b43.jpg

(Yes, I know the LED's are oriented incorrectly. I'm not done with the board yet as you might have guessed from the pictures. I didn't want to accidentally kill the board from some noob mistake without consulting you guys first before I power it on.)

I forgot to ask whether or not I need to use this IAC valve control thing or not.

https://www.diyautotune.com/product/...-39mod-kit-39/

Ok so this is the component layout described by Frank Westfield in the link you sent me, jhtong.

.https://cimg1.ibsrv.net/gimg/www.mia...ae1e2b58a4.jpg

This is the component layout described by Braneack in this thread: https://www.miataturbo.net/useful-sa...asquirt-13676/

https://cimg2.ibsrv.net/gimg/www.mia...8e09cd693e.jpg

Both of these are dealing with the same V3 Board, but Braineack was using an MS1 processor and Frank was using an MS3 processor WITH the Extra board, which as I have stated before I don't have or intend to use unless absolutely necessary.

The closest thing I have found to my setup was this thread: https://www.miataturbo.net/megasquir...k-right-62430/

But his board had weird stuff like ignition inverters, which I didn't think you needed except under special circumstances, according to Braineack in the thread linked above.
He also retained the MOSFET on the rightmost spot of the heatsink, which from what I can tell can be used for like 4 different mods depending on what you are doing.

I mean seriously. One dude will have 1/4 of the components missing on THIS side of the board and another will have 1/4 of the components missing on the OTHER side of the board, and people will say "yup thats correct!".
Correct according to what exactly? This is some voodoo **** that appears to just be passed down from thread to thread and build to build with nobody having real understanding of the boards except a few guys who came up with the "mods" in the first place.

why would you even consider looking at MS1 documents from 2006 to build your MS3 that was released in 2010 -- especially when hlaf the pictures don't work and the first thing it says is: NOTE: THESE DOCUMENTS ARE VERY OLD AND OUTDATED?

Well I wasn't sure if the daughterboard/CPU affected the setup of the mainboard, considering they are the same across all generations. That is why I looked at the other builds with more recent processors, and referenced them in my posts above. All I need is some confirmation as to which one to use.

http://www.msextra.com/doc/pdf/MS3ba...rdware-1.4.pdf

This PDF manual has gotten me farther, but I still don't know what needs to happen on the board for the miata specifically.

follow Frank's guide, not mine.

He cut apart his daughter board and left off all but one of the transistors on the heatsink, as well as using the extra board. This doesn't seem accurate to a base MS3 build.

that's just the silly way he built a harness -- ignore that.

the rest of the documents -- to that point -- are spot on.


I'm working on releasing all my own how-to documents soon, but it wont till after the new year probably.

If you're building a MS3, you sure as hell be using the "extra board" and making an ms3x.

So if I were to use the Extra board, I can follow this component diagram on his website?

https://cimg0.ibsrv.net/gimg/www.mia...fc8ff0ccfe.jpg

From there, what jumpers and mods would I have to perform to use it in a 97, assuming I use the GM AIT?
His website gives two pictures of the same board, each with very different setups as far as jumpers go, and no shots of the back of the boards either.


The first one I think is correct according to his diagram above.

The second image is batshit insane and I have no idea why it's on there.



https://cimg1.ibsrv.net/gimg/www.mia...25c805d74a.png
https://cimg8.ibsrv.net/gimg/www.mia...345f3e42d8.png

Franks guide tells you what jumpers you need to do inside the board. Buy the ms3x board and then follow franks guide. Then wire the ms3 harness to your connector.

https://www.diyautotune.com/product/...xpansion-card/

https://cimg4.ibsrv.net/gimg/www.mia...754e15cf3c.jpg

im assuming that's the alternator control circuit built on that one picture--an unnecessary mod to make--the expander card takes care of that.


In going to quote myself, again, here:

Alright thank you Braineack. I ordered the expander board, the two 24" harnesses for the MS3 and MS3X, as well as the open element GM AIT kit with aluminum bung.
I also changed my mind about the UEGO and went with an MTX-L since it can do serial with the expander board, but I will cross that bridge when I get there.

I will take pictures of the at different levels of completion. PM me if you want any for the guide you will be making.

Correct, it's the alternator circuit and most people don't use it. I still use it in my builds because it's rock solid, takes 10min to build and saves me the frustration of having to struggle with the software settings. Or maybe I'm just old and feel more confident with a hardware circuit 🤗.

The reason my component diagram has so little components is because the MS3X (expander card for the MS3) already has these circuits on board. So there is no point in duplicating them on the mainboard. Should you not use the expander board, then yes, you would need to build the extra circuits. It'll be a lot easier, quicker, less frustrating and better to get the MS3X card though.

Somerhing nearly nobody does is integrating the ecu connector inside the case. I do because I hate db37 connectors and extra wiring looms. I admit that it gets crowdy inside the case though 😂. The outside and wiring is very neat though.

$0.02

thanks for the reply, frank!

Btw, you can leave out even more components.
- Leds: these are invisible once the ecu is installed, so why bother?

https://cimg5.ibsrv.net/gimg/www.mia...668591ab0d.jpg


- The MS3X card has a usb port, so why bother building the serial circuit?
This last pic is how I build them (no leds, no serial). Without serial you have the option to use bluetooth or even wifi.

https://cimg1.ibsrv.net/gimg/www.mia...1add8c7b25.jpg

Thank you, the help is much appreciated. I feel better about this now.

One more question though; if using the DB37 connectors, should both of them, the one on the base board and the one on the expander board, be kept?
I just ask because I saw this picture from Oochi's MS3X build:

https://cimg3.ibsrv.net/gimg/www.mia...c619243287.jpg

It looks like both DB37 connectors are used, in which case I should add that to component map you posted, correct?

Thanks.

Is this "expander board" you're talking about the MS3x board, or a JBperf expander board? MS3x does not have serial wideband input.

No I bought the MS3X board. I was wrong about being able to run serial to the MS3X directly. According to this thread https://www.miataturbo.net/megasquir...-serial-69739/
you need to use the JBperf board you described in order to convert it to CAN, which the MS3X can read. Anyway, yeah, that's why I was going to do that later once I get this thing at least running.

how else do you expect to use the expander board, if it doesn't actually connect back to your car?

Well if I was smart I wouldn't be asking these questions now would I?

:)

Hey Frank, do you have a decent photo of how you connect the ECU connector to the board? TIA.

https://cimg7.ibsrv.net/gimg/www.mia...480b698231.jpg
https://cimg8.ibsrv.net/gimg/www.mia...e9b2b21d4d.jpg
https://cimg9.ibsrv.net/gimg/www.mia...01df570754.jpg
https://cimg0.ibsrv.net/gimg/www.mia...b4defad5ab.jpg
https://cimg1.ibsrv.net/gimg/www.mia...96a813cf94.jpg
https://cimg2.ibsrv.net/gimg/www.mia...152ab9184b.jpg
https://cimg3.ibsrv.net/gimg/www.mia...f7225f5674.jpg
Just a couple of screws. One of the connectors (I believe the 99) resuires no extra holes. For the 2 others, you need to drill a couple of holes, but theres no copper under the heatsink, so no problem at all. The 01 connector requires no cutting of the processor, the 2 others do.

I desolder both db37's and just run the wires directly from the ecu connector to where the db37's were. IMHO by far the best solution, but to each his own.

warning warning warning: pics 1 and 3 have the trimmers upside down!
The top trimmer is not needed anyway (replace it with a 100K resistor in the 2 outer holes).

Just finished my box. DIYautotune apparently is close to me here in GA so they got the stuff I ordered yesterday shipped to my house this morning. Very fast.

Anything look wrong here? I followed Frank's instructions. Image spam incoming.

(Don't mind the heatshrinked blob in the middle, thats the resistor. I moved it away from the board so it would be easier to solder.)

https://cimg8.ibsrv.net/gimg/www.mia...492a81327f.jpg
https://cimg0.ibsrv.net/gimg/www.mia...51353cb069.jpg
https://cimg3.ibsrv.net/gimg/www.mia...715d200ce2.jpg
https://cimg4.ibsrv.net/gimg/www.mia...d4d04fd499.jpg
https://cimg7.ibsrv.net/gimg/www.mia...53bddb1ff6.jpg
https://cimg8.ibsrv.net/gimg/www.mia...09c8b19bb7.jpg
Screws to the left of the mosfet are for visualization of the screws inside the spacer. Small on the bottom, long on the top.
https://cimg0.ibsrv.net/gimg/www.mia...0d1f4f6772.jpg
https://cimg3.ibsrv.net/gimg/www.mia...8ea7a80c22.jpg

So now that I have the box built, how do I know it works? I forgot to buy a jimstim :bang: and I also followed Frank's instruction on deleting the LED's...

I tried looking at this thread in order to do the software stuff, but I think it's outdated :) https://www.miataturbo.net/useful-sa...allation-7000/

Based on Frank's directions, I believe I go here Megasquirt Downloads Firmware and Software - Megasquirt EFI and download the MS3 firmware.
Download Virtual COM Port Drivers for driver to connect with USB, then upload firmware.

Download EFI Analytics Software Downloads | tunerstudio.com for tunerstudio, then somehow find a base map or use VEanalyze or something. I'm a bit confused with that part. Know of any good threads?

Let's hope this thing isn't dead from static! Any of you ever heard of killing these boards while building them? I grounded myself periodically touching a light switch screw on the wall, but I didn't have a reliable grounding strap.

youre missing q22 and q23 on the bottom.

The MS3x board is just a board with a bunch of output and input circuits on it. A lot of them used to be built on the mainboard. It connects to your ms3 card via 2 ribbon cables. It does not connect to the mainboard (or the main DB37 for that matter at all), think of it as a way to use all of the new ms3 functions that the mainboard doesnt support.

So yes, you need both connectors.

Thank you for the clarification aidan, and thank you Braineack for noticing that. I will put those transistors on immediately.

To load firmware, the MS3 needs a USB connection to a laptop, as well as 12v power input correct?
In order for me to load the firmware while the box is on the bench, can I connect 12v positive and negative to the mainboard DB37? (One on the bottom)
Looks like the positive 12v goes to pin 28 and the negative goes to pin 19.

I ask this because I don't have the mazda ECU connector yet, but would like to load the firmware before I put it in the car.

Nevermind, just got the connector in the mail from Mouser. I will wire it up and install firmware in the car.

Thanks for the pics, Frank. In your 4th pic, where are the wires from the connector going of to, at the right of the pic?

https://cimg6.ibsrv.net/gimg/www.mia...93378df66e.jpg
To the ms3x module.
I still find this the best way to do the wiring. Everything is inside the case and plug and play. Don't understand why people find it silly.

Ok so iv'e been doing this wiring stuff. Frankly, Frank, I find your pinout of the 96-97 harness rather confusing.

This is what is on your website:

https://cimg9.ibsrv.net/gimg/www.mia...ace8bb64b3.png
The real 96-97 ECU connector looks like this:

https://cimg2.ibsrv.net/gimg/www.mia...ff8e36d6f0.jpg

I realize that the "Connector 2" section has nothing plugged in. However, the only way to make you're diagram work, assuming you omitted the 2nd connector section, is if you switched the two outer sections of the now 3 section diagram.

Ideally, your diagram should look like this, that is, if you left out the "connector 2" section.

https://cimg8.ibsrv.net/gimg/www.mia...3d67fc64d0.png

Which brings me to my next problem. The mainboard MS3 DB37 pigtail available from DIYautoTiune do not have wires on pins 8 - 14, so the grounds that fall under those numbers in your diagram will lead to nothing. The wires for the mainboard pigtail run EXACTLY like this:

https://cimg1.ibsrv.net/gimg/www.mia...55f2701f3f.png

As far as the chassis grounding wires are concerned on the mainboard, which ones from number 15 - 19 should I plug in to the harness connector?

I would also like some clarification as to what you meant by "crank in" on pin 24 of the mainboard connector. This is the CAS signal correct?
I also am wondering what "OEM NB" does on pin 24 of the mainboard connector. I don't have an NB.

Stop making this complicated.

NB is not chassis code, it stands for Narrow Band. As in narrow band oxygen sensor. It clearly tells you in the chassis schematic and the MS schematic that is what the circuit is for.

If you wire it exactly like that pinout says, it will work. not sure why you insist that it is confusing? Seems simple to me and easy to understand.

For the grounds, add them to the connector.

For crank in, did you compare it to the schematics??

don't use Nitro IN for VSS input, use tableswitch.

yeah the diagrams are as looking at the male side, not the side you solder, and that diagram is a little backwards, but you have the idea.

Look, the schematic was flipped around and didn't accurately portray the connector it was describing. I don't see how you think that was easy to read in the slightest.

I'm not taking apart the $55 dollar pigtail I bought from the people who designed this system, because some guy who didn't even use the DB37s says some different wire combinations. In fact I bet they all go to the same grounding plane but whatever. I want to hear it from Frank himself.

I am not taking chances with my $600 worth of electronics and I am not "overcomplicating" this. It's already complicated and poorly documented. I'm just trying to make it less so for people who aren't doing this "add a connector to the case" asshattery.

I am one that didnt use the connector in the case and use both db37 to a diybob. I did it exactly as the ms3x wiring pic describes and it works just fine.

So I should use pin 28 of the MS3X connector for VSS and not pin 29, correct?

All grounds are interconnected. Just use as many grounds as are used in the diagram, and you'll be fine.

Ok, thats what I thought.

This just confirms it. https://www.diyautotune.com/support/tech/other/grounds/

https://cimg3.ibsrv.net/gimg/www.mia...02b9427c59.png

went and made a real table

tell me if I ****** up

https://cimg3.ibsrv.net/gimg/www.mia...e33d6cc26d.png


MazdaConnector Board DB37Pin DB37Color Description

1A Exp. 1 White-DarkBlue Main Fan (INJ G)
1B Exp. 4 White-DarkGreen AC Fan (INJ F)
1G Exp. 20 White-Purple AC Out (INJ H)
1K Exp. 30 Gray AC In (Datalog In)
1L Exp. 11 Gray-Red Clutch pedal switch (for launch control)
1M Exp. 28 Gray-Purple VSS (tableswitch in)
*1O Main 17 Black Chassis GND
*1O Main 18 Black Chassis GND
1U Main 37 Violet Fuel Pump

3C Main 23 Pink OEM Narrow Band O2 sensor
3F Main 22 LightBlue Thtottle position Sensor
3G Main 21 Yellow Coolant Temp
3I Main 26 Gray 5v Reference
3K Main 20 Orange Air Intake Temp sensor
3O Main 1 Black(in shielding) Sensor GND

4A Main 2 Shielding Sensor GND
4B Main 29 Red +12v
*4C Main 15 Black Chassis GND
*4C Main 16 Black Chassis GND
*4C Exp. 2 Black Chassis GND
*4C Exp. 3 Black Chassis GND
*4D Exp. 8 Black Chassis GND
*4D Exp. 12 Black Chassis GND
4F Main 24 White(in shielding) Cam Angle Sensor input
4G Exp. 32 DarkGreen tachometer input
4L Exp. 26 LightGreen-Orange tachometer output
4N Exp. 14 Yellow Spark A
4Q Exp. 9 LightGray-Pink Idle Air Control output
4R Exp. 33 Yellow-Orange Spark B
4U Exp. 19 White INJ A (cylinder 1)
4V Exp. 10 White-Pink INJ D (cylinder 2)
4W Exp. 16 White-Orange INJ B (cylinder 3)
4X Exp. 13 White-LightGreen INJ C (cylinder 4)

* denotes multiple wires sharing the same mazda connector pin

if Pin 28 is tableswitching, then yes. Nitrous IN wont work for the VSS input (or almost anything else for that matter).


The wiring diagram is good, but we all used images of connectors that are "mirrored" or backwards or whatever. I'm working on correcting that.

tables do nothing for me, im not even going to look at it, cause i know that visual image of the connector and the wires is correct -- so no need to reinvent the wheel. When you build the harness, are you going to want to look at a diagram or a table?



I totally understand you wanna get this right.

Another thing you can add is another spare INJ output to your CEL light. otherwise i think youre all set.

It's actually slick and clever, i just dont like how crammed it is, and unflexible it is. Like let's say i had to swap out the expander card for some unknown reason -- that's a lot of effort removing it now (instead of [1] wire attached).

That's my only issue with it. It is really really hard to add any sort of expansion, or extra cards inside.

Anybody want an ms3? Has lots of features and pre wired for my specific harness :)

To each their own I guess. I much preferred the table I made when building it. I could then just cross reference the number/letter combo to the connector, but whatever it's just semantics. The flipped around mirrored image whatever confused the hell outta me looking at it for the first time. Plus it was like 11PM...

So now I am done with the harness. Here it is installed in the car:

https://cimg3.ibsrv.net/gimg/www.mia...25684471c4.jpg
https://cimg4.ibsrv.net/gimg/www.mia...ab14e9b50b.jpg

So now I have to take that beautifully wrapped kapton tape off to run the INJ circuit for the CEL.
Which board's INJ circuit are we dealing with here? I assume MS3X, in which case the only one left is INJ E on pin 7.
Which number/letter combo on the miata connector goes to the CEL light?

On a separate note, I would like someone to confirm that this is the correct setup for pinning the GM AIT sensor into the stock 97 connector.

https://cimg3.ibsrv.net/gimg/www.mia...3381a2de51.jpg

I also have a question about where I should tap the +12v for the MTXL. Looks like people say the blue wire under the dash from the ignition switch but i'd like to see what you all say.
The rest of the wires go as described, right?

WHITE dimming wire will just be grounded to the body somewhere for now.
BLACK Engine grounding wire for the MTXL goes through the firewall and onto the fuel rail ground bolt.
YELLOW wideband wire goes through the firewall and into the signal pin of O2 connector. I'm having trouble figuring out which one is the signal pin. Looks like there are 4 pins.

https://cimg5.ibsrv.net/gimg/www.mia...cb86fff770.jpg

I'm planning on taking out the front O2 sensor and using it's bung for the wideband. I'll just disconnect the rear O2 sensor from the harness. This sound reasonable to you all?

for O2 signal, its the OEM NB wire on your harness. just use that since you wont use/need the stock sensor. For the power, i used the white/red that powers the ecu. That way the sensor stays powered up during cranking and doesnt go through the heating stage multiple times.

Ok that makes sense. Is it a good idea to use one of the megasquirt grounds for the wideband? Seems like I could just tap into one of the chassis ground wires on the harness I just made. Although I wonder if running power through the board for this thing is a good idea anyway, considering the heater draws 3 amps. Where do you run your ground Jesse?

Back to the CEL question. I found this thread:
https://www.miataturbo.net/megasquirt-18/ms-wiring-questions-fan-control-cel-74024/

He discusses oil sensors and CEL, but he had a 90-93 and I saw no mention of pinouts of where exactly the CEL light goes to the ECU. I just need to figure out where on the OEM harness the damn bulb runs to... I'd rather not have to pull the dash and break out the continuity tester just to find out.

Use Google.
Find 96-97 wiring diagram
find cluster pinout
Trace to ECU.

Instead of asking here you could have already found it out.
​​​​

I find it hilarious that you use your computer to log into an internet forum to bitch about having to physically trace a wire in a car for which schematics are plentiful.

pages 8 and 9
http://www.yorbalindamiata.com/images/wiring/96sys.pdf

1E yel/blk

You know if you guys really get this assravaged about normies invading your board, why do you even bother replying? Or even coming here at all? Just sage and move on.
That is, unless you ENJOY bitching about me bitching about a wire...

In other news, I got the AIT mounted in the airbox. Drilled a hole and threaded the plastic with a 3/8th NPT tap. Pictures for your viewing pleasure:
https://cimg4.ibsrv.net/gimg/www.mia...e73aaaf50e.jpg
https://cimg7.ibsrv.net/gimg/www.mia...943f83628b.jpg

Index of /garage/Wiring Diagrams/Wiring Diagrams 1990-1996/

use the schematic to identify what wire it is. It isnt absolutely necesary to do the CEL

Hey now we're getting somewhere. Thank you

we can only spoonfeed so much until we run out of baby food...

do not wire your WBo2 FROM the MS, wire it using the wires leading up TO the MS. The main power and ground at your harness is the best place. Always use (white/red) power wires. Why in the world would you want the MS to provide the power?

After I gave you the page number pinout and wire color. lol. You really do suck at this whole computer and internet thing huh?

Good luck, with your intelligence and emotional maturity, you'll need it around here. :giggle:

i use the white/red wire in the harness that FEEDS the MS and one of the grounds that FEEDS the MS. I foget which one exactly i used. Either 2A or 2B on my 93.

Got it to idle on the first crank. AFR is around 9.5 and my advance was ~ 7 degrees.

I can't tell if it was that rich because of the warm up enrichment table or because of the base map itself. It was like 45* F outside at 4 AM and my friend and I couldn't feel our toes, so we called it quits for now. I threw the stock ECU in and went home.

Does anybody have an MSQ file that will work for the latest version of tunerstudio? I found a few but they seemed not to play well when I loaded them in because they were out of date or something.

MegaSquirtPNP by DIYAutoTune.com

The pro maps are the latest DIY autotune basemaps.

I ended up running +12v from the car's harness (white/red), and then I ran the ground straight to the head. I spliced the dimming wire into the rear running light power. It all works.

As for the O2 signal wire, I ran both the wideband and narrowband outputs to a 2 position switch I mounted in the dash, and then ran the switch output to my harness O2 signal wire. I can now switch freely from wideband to narrowband for swapping my ECU on the fly.
Conversion from megasquirt to OEM takes around 4 minutes on my naturally aspirated setup.

It's better to ground it as close to the ECU as possible to remove any grounding offsets between the wideband ground and ecu ground. Im sure you notice the MS's AFR gauge doesnt quite match your wideband controller's own.

why did you run a switch? your wbo2 has two outputs -- one can send a linear 0-5v, the other can mimic a 0-1v narrowband.


glad it's running.