PCB v3.0 mods

[panel]

If I was to use this mod to add a fan....how do you get the wire to the DB37 connector?

https://www.diyautotune.com/wp-content/ ... xample.jpg

This is one example of what you can do, in this example I used the JS3 output from the MS-I CPU as the input into this circuit (telling it when to switch on/off) and the output routes to Jmp SPR1 which sends the signal out to the DB37 on pin3 which is a pretty good choice since on the v3 it’s not used for anything else. You’d then use pin3 on the DB37 to control your relay which controls your electronic doodad of choice — electronic fan.

Or if I used this boost mod....

Same here:

https://www.diyautotune.com/wp-content/ ... 00x355.png

[GS guy]

Panel,
I was able to re-purpose one of the DB37 pins for my boost controller - don't remember what the pin was originally for off the top of my head? I was able to use an existing wire in the RB cable and connect this circuit through and into the RB for the IAC circuit. Bypassed the relay for direct "input" to MS. Some pics a couple of posts down on this page:
viewtopic.php?f=19&t=139036&start=45

To be honest - the Q16 circuit re-purpose was a neat trick, but getting it into the DB37 was a real PITA. I recall having to solder directly to the little clipped "stub" sticking up from where the DB37 interfaced with the board. That pin was one of very few available to re-purpose as I remember, and about the only one I could access on the back of the board.
Now I'm faced with adding another I/O re-purposing one of the LED circuits. This time I'm just going to run another external output - separate wire coming out of the case with a separate connector.

I guess you could maybe add a separate DB9 connector to the end-plate (maybe at the LED location?) if you had a couple or more circuits to run out, or just run a couple wires directly out of the case and a little pigtail.
Jeff

[ps2375]

There are labeled spares and if you aren't using the IAC pins, those are there too. Just a jumper wire from ckt in proto area to labeled SPR near db37

[panel]

Looks like I have SPR3 and SPR4......just need one more. FIDLE maybe?

[Piledriver]

So you are using IAC1-4?

[panel]

I just wired them up because I thought you had to in step # 13.4 Jumper wires 23) Jumper wires. I'm not actually using an IAC valve. I also wired the CAN jumpers - top side of board, JS6 to SPR1 (CANH) and JS8 to SPR2 (CANL). I wont be using CAN either. Looks like I assembled first but didn't read /understand what I could leave out and what was necessary. I also need to run an Autometer tach ....do I take that off one of the IAC1-4 ?

[Chip Birks]

What manual did you use?

[panel]

http://www.msextra.com/doc/pdf/MS2V30_Hardware-3.3.pdf

What manual did you use?

[Chip Birks]

Did you actually build the ecu? Or just doing the jumpering?

[Piledriver]

You cannot use the IAC outs to trigger a HV-trigger type tach, due to built in clamp diodes.
It can run a 5v or 12v logic compatible tach with no HV "kicker" circuit. (inductor/relay coil etc)
Remember--- There are 4 IAC lines but really only 2 signals, IAC1A is always inverted from IAC1B etc.

[panel]

I purchased a MS1 built board from someone who bought a DIY kit from DIY Auto. I'm in the middle of adding the MS2 daughter board that I got from Mario and also doing some mods on the way.

Did you actually build the ecu? Or just doing the jumpering?

[panel]

Man I'm I lost. I guess I'm not understanding this very well then?

3.5.5
Tacho output
A tacho output typically provides a 0-12V pulsed signal that is suitable for driving an aftermarket tachometer (rev
counter.)
Some older tachometers expect the high-current "spike" from the ignition coil and may not work directly with a 0-
12V signal.
Outputs IAC1A, IAC1B, IAC2A, IAC2B provide a 0-12V signal. If these are not used for a stepper idle valve,
they could be used directly for a tacho output. Ensure that the jumpers in section 3.5.4.3 are connected.

You cannot use the IAC outs to trigger a HV-trigger type tach, due to built in clamp diodes.
It can run a 5v or 12v logic compatible tach with no HV "kicker" circuit. (inductor/relay coil etc)
Remember--- There are 4 IAC lines but really only 2 signals, IAC1A is always inverted from IAC1B etc.

[panel]

Man I'm I lost. I guess I'm not understanding this very well then? So are you saying that the Autometer tachs are a higher voltage tach?

3.5.5
Tacho output
A tacho output typically provides a 0-12V pulsed signal that is suitable for driving an aftermarket tachometer (rev
counter.)
Some older tachometers expect the high-current "spike" from the ignition coil and may not work directly with a 0-
12V signal.
Outputs IAC1A, IAC1B, IAC2A, IAC2B provide a 0-12V signal. If these are not used for a stepper idle valve,
they could be used directly for a tacho output. Ensure that the jumpers in section 3.5.4.3 are connected.

You cannot use the IAC outs to trigger a HV-trigger type tach, due to built in clamp diodes.
It can run a 5v or 12v logic compatible tach with no HV "kicker" circuit. (inductor/relay coil etc)
Remember--- There are 4 IAC lines but really only 2 signals, IAC1A is always inverted from IAC1B etc.

[Piledriver]

If you re-read what you posted (and what I said) carefully there is zero conflicting info.

They can be used for tach signals, just not for old-school tachs that need a HV kick circuit.
I added the "why" that is the case (clamping diodes in the CPUs IAC drivers).

You could use them if they are only driving a buffer amp that could drive a HV tach.

[panel]

thx for you patients Pile.

To confirm for the TACH circuit , make sure these are all done (I'm not running an IAC valve):

a) JS0 to IAC1A
b) JS1 to IAC1B
c) JS2 to IAC2A
d) JS3 to IAC2B
e) JS9(+12V) to S12C

Then I can tap into either one of these outputs IAC1A, IAC1B, IAC2A, IAC2B to provide a 0-12V signal ?