Troubles communicating with Megajolt E

General Topics for configuring, operating and tuning the Megajolt. Also see the <a href="http://www.autosportlabs.net/MJLJ_V4_Operation_Guide">Operation Guide</a>

Moderators: JeffC, rdoherty, stieg, brentp

Post Reply
WhatDidIDoWrong
Posts: 8
Joined: Fri Mar 09, 2012 6:15 pm
Location: United States

Troubles communicating with Megajolt E

Post by WhatDidIDoWrong »

I'm a new user to Megajolt. I have an EDIS 4 I'm trying to get set up on my old VW with a Megajolt E unit I just got. The car starts and runs fine in limp-home mode at 10 degrees. I just got the Megajolt E unit a couple of days ago and hooked it up. I double checked all of the wires and the green light comes on but I'm not able to get a connection to the computer to program it. I also have the unit MJ unit hooked up to the EDIS but there is no change in idle from what I can tell, so I'm assuming the unit is not programmed at all, correct?

I have a very short (8") USB to DB9 serial cable I paid $25 for from a computer store which has a male serial end. I didn't get the correct RJ11 to DB9 converter plug with the unit when I bought it. I found out the hard way I cannot get one of these little plugs locally. I tried yesterday using an additional USB cable from the converter DB9 plug end to the MJ unit with the correct end pieces I could find to convert from (the MJ unit) RJ11 to USB to DB9 to USB. I got C++ errors in the Configurator program a couple of times and it couldn't communicate. Did I mess something up in this process on the unit itself?

Then last night, I tried cutting up an old RJ11 cable and hooked up the fours wires of the RJ11 directly to the pins on the male end of the DB9 converter plug, if I read it correctly the number five pin would be the rightmost upper pin on the DB9 converter plug (facing the plug), correct? In the picture below the far two right pins I have wired are the grounds 3/4 to pin 5 (as I understand it), middle wire with blue tape is 2 to pin 3 and yellow is 1 to pin 2.

http://www.autosportlabs.net/MJLJ_V4_Operation_Guide

The green light is still on when I have the ignition on but I still cannot get a connection to the unit. I tried a different laptop and different USB ports. The hardware says the USB converter was installed correctly and is functioning correctly in My Computer settings. Is there something I could check at this point on the MJ unit?

Image

WhatDidIDoWrong
Posts: 8
Joined: Fri Mar 09, 2012 6:15 pm
Location: United States

Post by WhatDidIDoWrong »

Nevermind, a friend of mine who deals with electronics was able to piece me together a cable that works now. What a pain the butt :(

brentp
Site Admin
Posts: 6277
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Sorry it was so difficult! Are you fully up and running now?
Brent Picasso
CEO and Founder, Autosport Labs
Facebook | Twitter

WhatDidIDoWrong
Posts: 8
Joined: Fri Mar 09, 2012 6:15 pm
Location: United States

Post by WhatDidIDoWrong »

It works now. It wasn't getting a RPM signal, etc. once I was able to communicate with the MJ so I adjusted the VR sensor closer to the trigger wheel and it works now. Still getting familiar with how to program it. Just the older USB->DB9->RJ11 connection thing took me by surprise and was a little more than I expected to get through.

One thing I don't really understand is the load bins. Is it necessary to specify these or could I leave them all '0'? What do they do, and what is the advantage of them? How do you determine the amount of bins? Thanks.

Image

Post Reply