MicroSquirt.com read only forum (Jan.15,2018)

Ok, today marks my first really bad day in years of MSing

I just got a micro module from DIY-EFI for use on my bike.

The bike has already been wired to a DB37 pin connector for use with a V3 board, but the board was simply too large to be usefull.
So since I was planning on using the map mixer curcuit and adding a couple other circuits i figured using the module would be an easier way to go ( eventually just stack it on top of another board with the additional circuits and coil drivers etc ).

In ant case, As the bike already had a DB 37 pin connector, and I am still doing a ton of testing, I wired up a male dB 37 pin connector to the module, figured this would allow me to use the jim stim as well. I used the ledjer on the back to hook up the inputs, and 12v, vref, injector wires and ground wires.

plugged it in and attempted to load code, and no go.

after a bit of probing I discovered that Vref was only ~1.7 volts. I quickly dissconnected it from the stim and double checked the wiring :

Pin #1 (module) 12v was hooked to pin 28 (DB37)
Pin #15----------Vref-""""""""""----to pin 26 """"""""
Pin #5------------CLT------------------pin 21
pin #9------------MAT-----------------pin 20
pin#13-----------TPS------------------pin 22
pin#21-(opto-)------------------------pin 6 (spare 4 v 3)
pin#23-(vr1in+)-----------------------pin 24 (tach in)
pin#27 (O2in)-------------------------pin 23
pins#30&32(inj1)---------------------pins 32&33
pins#34&36(inj2)---------------------pins 34&35
pins#35 to 43 (ground)--------------pins 14 trough 18 all ground...

I did not see and pin out for pins 45 and 47 on the module J2, but 45 tested 0 ohms to ground, so I used a short wire from that pin to short out pin 8 (boot loader) for loading the code.

As I was writing the chart above down I was again checking all the connections, and again they all look ok.

So, once I realised that my Vref was way low, I started checked the voltage in (12v J2 pin 1 ) and it was ~1.7 . this was weird, then I noticed that the poly fuse and 3.3v regulator on the jim stim were getting hot. I unplugged it from the micro board and powered it back up, it would power up untill the poly fuse kicked in. Now it had just been hooked to a V3 board and had been running fine for over a day on my desk, I hooked it back up to the V3 board and powered it up breifly, still worked while the poly fuse was allowing power through. I eventually traced the stim issue to a bad zener diode (D4 jim stim) and disconnected it.
So I am wondering what if anything on the micro-module could have caused this ( the bottom of the stim is insulated to prevent shorts ).

After I isolated that issue, I tried it on the micro-module again, still only ~1.2 volts on the Vref, Then I completelly dissconected the Vref wire from the stim, ( cut it, Pin 15 (J2) & 26(db37) and tried again.

This is where my heart sank, turned it on the first time and i still got ~1.2v, ( both the Vref and 12vin ), turned it on a second time ( after checking all the wires again ) and got 12v on BOTH the V12 in and Vref . I still, after numerous checks and playing it all back in my mind, cannot find where i may have messed it up, but 12v on the Vref im fairly certain the board is dead.

I keep thinking i must have messed it up somewhere, but I cant find and mistakes. Have I wired it wrong somehow???? Is it possible that i just got a bad board?

If I have to fix it, I am fairly sure i will need a new 5v regulater, a new MC9S12 chip ( although I dont know how to load the bootloader ) , what else could be toast.

Very dissapointed, I find it hard to belive that i just got a bad one, i know the micro squirt has been tested and used ad nausium. But I can't find where i may have messed up. If anyone gets a chance, PLEASE double check my wiring and let me know.

As far as I know the one true way to fry a board is to short the Vref to 12v, so i took extra care in making sure i got those wired right, but something doesn't add up.

Thanks, Joe

Dang it, just realised this is not in the forum thread i wanted it in, i meant to post it in the module thread, not the general info. Don't know if it makes much of a differance, but i don't want to double post, so if a moderator wants to move it to a more apropriate thread that would be sweet.

Thanks,
Joe

Ok, possibly not so bad afterall.

I ran just a 12v to pin 1 and a ground to pin 35, tested Vref and it was 4.9v.

I then was able to load code( 3.0.3t), and get it talking to TS. I was seeing CLT and IAT, no TPS cause the Vref was still dissconnected.

Though I am seeing RMP, the injector LEDs were not firing.

However, and this is where i need to do more digging, it does not seem to be getting ground through the 5 pins I hooked up ( see above ), only when I hard wire pin 35 (J2) directly to the ground screw terminal on the stim will it stay powered up. looking at the jim stim it appears that the pins i chose for ground do not actually go to the ground plain.

However, now i still have issues with the jim stim, 3.3v regulater is still getting hot and no LEDs, I will look at it some more tommorow.

After my initial panic at seeing 12v on the Vref, i looked at the DB37 pins i used for ground per the V3 schem. While they are grounded on the V3 board they don't appear to be grounded on the jim-stim...

So, now what I need to do is figure out what those pins do connect to, It makes no sense that they would have any kind of power to them, as that would cause a short to ground once connected. But I am having issues with the jim-stim now and I doubt its just a coincidence. Will be over on the stim forum to see if i can sort it out.
So, FYI If the microsquirt isn't grounded, you will see 12v on both sides of the 5v reg! ( no current flow = no voltage drop elec 101 )

Joe