AGreen

iTrader: (11)

I know this has been covered a few times, but I just can't find my answer.

Now that I've got my MS working and car running, I need to figure out how to make the MS turn on the E-fan or BAC. I used the DIYautotune writeup for building the ECU, then TRIED to use Aaron's writeup for wiring it up. Aaron's writeup has the fan triggered from pin 25, but that got used after figuring out that I HAD to follow the same writeup for building and wiring.

I'm using the stock BAC valve, and it's wired up just like Aaron said. Pin 30, +12v, diode between the wires. I assume you're supposed to wire it somewhere on the zeal card, but all the DIYautotune writeup says is, well, just that. No specifics. Then, what do I use to control the fan? Right now that wire is just dangling. There has to be some sort of writeup somewhere for this that I've missed.

muythaibxr

The BAC can be wired to the IDLOUT via on the zeal board through any spare db37 pin. Wire the idle input on the zeal board to the middle pin of the FIDLE transistor.

The fan will need a relay, which you will wire to any of the other outputs on the zeal board. Then you wire any of the corresponding inputs to a spare CPU pin (such as one of the IAC pins).

Ken

AGreen

iTrader: (11)

When you mean through any spare db37 pin, do you mean that I need to run a jumper wire from IDLOUT to the bottom of the db37 solder connection?

And I have the fan already wired up with a relay, it's just that I don't know which "spare" I can hook it up to. Pins 25, 27, 29, 31 are all the IAC outputs, but they're taken up by the CAS and coils.

AGreen

iTrader: (11)

This is my harness wiring as of right now. I used Aaron's as a guide, but made it work with the DIYautotune writeup for building the ms2v3 with the zeal board. As it sits now, the BAC isn't doing anything, and most importantly, I can't get to normal operating temperature to tune the ecu because I have no cooling fan! The wire is dangling, as is pictured on the schematic.

AGreen

iTrader: (11)

Whoa, now I'm confused. I just took another look at my board and realized that IDLOUT is already taken up. Like I said, it's wired up per DIYautotune's instructions, so IDLOUT is connected to the banded end of D8, and IDLIN is connected to the bottom of R19. So now what?

Sorry about all these questions, I've been doing some serious searching and can't find my answers!

Is there a schematic drawing of the MS2 v3 card?

Aaron Cake

iTrader: (1)

Think of it this way:

The Zeal board takes the place of all the mods you would generally do to the main Megasquirt board. So if you want to use the Zeal board with the rest of my writeup, you would just proceed as if the Zeal board is the additional VR circuit, BAC mod and extra output. So follow my writeup to connect the outputs of the Zeal to the corresponding pins on the DB37 instead of wiring those pins to the mods you make on the main board. The important thing to remember is to only follow one writeup when deciding the pinout of the DB37.

If you followed my writeup, then 3 of the IAC pins would have been used for the coils, 1 for the fan, and then two of the SPR pins used for the CAS. You can wire things up however you want. If your IAC pins are taken, use one of the SPR pins for the fan. Your BAC connects to the F_IDLE, which is now connected to the Zeal internally if it is wired correctly.

Your F_IDLE should connect to the Zeal card via D8, then the IDLE input on the Zeal card should connect to R19.


http://www.megamanual.com/ms2/pcb.htm

AGreen

iTrader: (11)

So with the way it's connected now, my bac should work. I think I may have a bad BAC valve then. I'll have to check to see if I'm getting signal to it before it's condemned.


This was really what I was trying to find. I couldn't figure out which pins were spares. This also answers my question as to why the fan kicked on when I just chose one pin at random. The pin I plugged it into was #12. It was the first one right after the 4 ground wires. Turns out, it's ground too



Thanks for the help guys. Getting my car running again means a whole lot to me after all the work I've poured into it. I'm especially anxious to drive it since I started this BEFORE my last deployment.

Much appreciated

Aaron Cake

iTrader: (1)

Is the diode on the BAC valve connected properly? The banded end needs to face 12V.

AGreen

iTrader: (11)

It wasn't. I figured that one out about an hour after my last post. Stupid stupid.... Of course it won't work with all the voltage shunted around it

I think I may have fried something though. I fixed the wiring, but it still wouldn't work. Through my testing, I got the bac valve to click full open by jumpering 12v and ground to it. With the key on, engine off, megatune says that the IAC duty is around 50 percent, so it should be at least a little opened, but it won't open at all.

However, before fixing the position of the diode I was getting less than a volt. Now I'm getting around 10.5v DC. I know it's pulsed, and I don't have a scope to watch it. The valve should at least move though, right?


Now, back to the fan. For some reason, I can't get megatune to configure the ecu to kick it on. I plugged the control wire in to pin 3, the first spare on the DB37. But if I go to port settings, all I get for options is:
FIdle - PM2
Injection LED - PM3,
Accel LED - PM4,
Warm-Up LED - PM5.
IAC1 - PT6
IAC2 - PT7.
Knock Enable - PA0

So the real question is, assuming I have it in the correct "SPR" position, how do I get megatune to apply ground to that wire when coolant temp gets to 195?

muythaibxr

How is it wired ?

It should have +12v going to it from the harness, and the other pin should go to the MS FIDLE pin.

IF you have a digital multimeter, most of those have a duty/frequency setting. You could hook that to the wire going to the FIDLE pin and check that the duty/frequency are correct.

Also double check that you installed the transistor for idle with the proper orientation.


Assuming you chose a pin on the DB37 that actually has a via associated with it (one of the IAC pins or one of the spare ones), you need to wire that back to the daughtercard. I typically use IAC1 or IAC2 (JS1 for IAC1 or JS3 for IAC3).

Ken

AGreen

iTrader: (11)

Yes, that is how I wired it.

I don't have a multimeter w/ duty or frequency, but I could get one. I didn't think of using that

Yeah, all the IAC pins are taken. See the diagram I posted for how I have mine wired. Pin 36, the IGN output, goes to the leading coil. So this is why I chose SPR1 (pin3) as the output for my fan, but I don't see where it has a via. So does this mean all my outputs are taken?

AGreen

iTrader: (11)

OK, well, maybe I have it now.

If I want to use one of the spare pins, I'll have to tap into one of the LED's or "knock enable"

I want to use knock enable. I don't have a knock sensor, so it'll do me no good.

So, in order to do this, I'll have to get myself a ZTX450 transistor and drop it in the proto area. Then connect a 1kohm resistor to its base, then to JS11. Then wire the emitter to ground, the collector is then jumpered to SPR1.

Then I can go into megatune and configure the generic port settings to "knock enable" when coolant >195 etc...

Is this correct?!!??!

muythaibxr

The zeal card has spare transistor outputs for driving relays. You can wire that up since you have it already instead of addig to the proto area. I also do not think you understand when I say IAC. You are talking about db37 pins. I am talking about JS1 and JS3 on the MS2 daughtercard itself. You cannot use the LEDs as spare outputs, those are already driving spark.

AGreen

iTrader: (11)

So I could jumper JS11 to IN2, and OUT2 to SPR1, and set it up like that using "knock enable" at coolant >195?

AGreen

iTrader: (11)

I jumped the gun and did it. It sounded right, and it was !!! My fan works, thanks alot!


But the bac still isn't working for some weird reason. I got a fluke w/ % duty. Megatune says 57%, fluke says ~58%. Ok, that's good. I still have +12v at the red wire too. The BAC still doesn't do anything when plugged in though. I used my bed-o-nails leads and checked for %duty when plugged in, and it's still the same. I also checked to make sure my connector was good, so I grounded the non 12v side (using the bed of nails lead) and the BAC clicked full open. Ok, so this eliminates wiring, bac, and ecu. Wait, there's nothing else that it could be, right?

Unless it's not getting enough current?

muythaibxr

The transistor might not have liked when that diode was backwards.

Ken

AGreen

iTrader: (11)

Is there some testing I can do to find out if something has gone bad?

AGreen

iTrader: (11)

And, if the transistor turns out to be bad, do I have any other choices for transistors aside from the ZTX688B-ND? I'd like to be able to stroll down to the local radio shack and pick up one, but they don't seem to carry those. They do, however, carry the rugged TIP120. It's an npn as well, but I want to make sure that it would be ok.

muythaibxr

TIP120 would be fine.

AGreen

iTrader: (11)

Yeah! Works great now! Guess I burned out Q5 with that backwards diode