Problem switching MAP's

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
910esprit
Posts: 46
Joined: Tue Feb 26, 2008 10:07 pm
Location: Portsmouth england

Problem switching MAP's

Post by 910esprit »

I guys, firts post from a newbie, i have got to the stage where i will be installing everything very soon and have been testing (playing) with the MJLT. But i seem to have problems switching MAPS i.e i can't, i think i am doing everything right, i have the boxes checked on the software but i can't seem to get any response when shorting option input to ground/12v (with resistor). Am i missing something here or have i damaged something.

don't think i have but will there be any damage if 12v splashed onto optin input. Just a thought.....

910esprit
Posts: 46
Joined: Tue Feb 26, 2008 10:07 pm
Location: Portsmouth england

Re: Problem switching MAP's

Post by 910esprit »

910esprit wrote:I guys, firts post from a newbie, i have got to the stage where i will be installing everything very soon and have been testing (playing) with the MJLT. But i seem to have problems switching MAPS i.e i can't, i think i am doing everything right, i have the boxes checked on the software but i can't seem to get any response when shorting option input to ground/12v (with resistor). Am i missing something here or have i damaged something.

don't think i have but will there be any damage if 12v splashed onto optin input. Just a thought.....
what no reply?????????????????????

brentp
Site Admin
Posts: 6282
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Hello,

Sorry we missed your post. Based on your description, it seems you have followed the wiring instructions here?
http://www.autosportlabs.net/MJLJ_V3_ve ... E_3.1.0.29

After wiring it up, you may want to put a volt meter on the input pin to prove the correct behavior is occurring. Also put your meter on the cathode side of D1 (the side of the diode with the stripe) to ensure +5v/gnd is seen as you switch maps.


The configuration software can be set to notify you when the option map switches. There are two things to set:

1. Enable in controller firmware. When selecting the check-box under global config options, make sure you click the button 'write options' so the setting is written to flash.
2. Enable notifications in software. this will alert you when the map switches.

Instructions for both are here:
http://www.autosportlabs.net/MJLJ_V3_Op ... igurations

Not sure how much water 'splashed' onto the option input, but I'm sure you've dried it off by now. It's highly doubtful anything bad happened.

Let us know what you find out.
Brent Picasso
CEO and Founder, Autosport Labs
Facebook | Twitter

910esprit
Posts: 46
Joined: Tue Feb 26, 2008 10:07 pm
Location: Portsmouth england

Post by 910esprit »

brentp wrote:Hello,

Not sure how much water 'splashed' onto the option input, but I'm sure you've dried it off by now. It's highly doubtful anything bad happened.

Let us know what you find out.
Thanks Brent will give it a go.

Sorry, i was not very clear with my expressions, 12v 'splashed' onto the input (was meant to mean) that due to the temporary wiring loom that i had quickly put together i may have touched the input to the 12v supply (without the 1k resistor) accidentally for a brief period. Would this have caused any damage?

I am not going to try again until i have finished the loom properly. Hopefully this week end.

910esprit
Posts: 46
Joined: Tue Feb 26, 2008 10:07 pm
Location: Portsmouth england

Post by 910esprit »

I have now got the MAPs switching properly, turns out that i had put 12v straight across the input.........Whoops.
It fried diode D1 and burnt the track off the board. New diode fitted and link wire on the board and every thing is now OK.
I have also used the 5v reference from the TPS out put by putting a 1K resistor where L1 usually lives.
Thanks for the advise Brent.
Should be fitting to the car with in the month. I will then post pictures.

Post Reply