Microsquirt No Communication

[hc08]

I just got two Microsquirt units (plus two 8' wire harness) from DIYAutoTune and I have been unable to establish communications with either of them. I have been running with a MS2 and Tunerstudio without issue for a while now, and decided to make the switch to Microsquirt for the smaller size and weight.

I have checked the wire harness going to MIcrosquirt and I believe it is wired correctly. The battery supplies ~12 VDC, and checking +12V in (Pin1) against PGND (Pin22 & Pin23) with a multimeter yields the battery voltage. Checking Vref (Pin28) against SGND (Pin20) yields ~5 VDC as expected. However, when I plug in the cables (jack -> serial -> usb) to my laptop, Microsquirt is not detected. The same serial -> usb cable (Gigaware Usb to Serial cable with Gigaware USB to Serial drivers installed) works just fine with my old MS2. Does anyone have any ideas as to what is wrong? I have spent a long time trying to diagnose this and I am starting to think that both Microsquirt units must have had faulty communications upon arrival (what are the odds)...

drivers.png

portcheck.png

setup.jpg

[jsmcortina]

Portcheck is working, so what's the problem?

If you are having TunerStudio problems, then you might be best posting in that sub-forum.

James

[hc08]

The problem was resolved while this post was awaiting moderation. Turns out I had to swap the serial transmit and serial receive wires going from the jack to the ampseal. Not sure why those would have been swapped around on a stock harness bought from DIYAutoTune. Don't think it was any fault of the serial -> usb cable (null modem vs. straight through), because that still works just fine on the MS2 unit.