Mac not detecting MS2PNP

[Dawskip]

So, I got my megasquirt, connected it, threw a base tune on, all was good. I pulled that engine and just dropped in my turbo engine, and now when i go to connect to the ecu, no cigar. It’s not appearing on my Mac, tuner studio isn’t reading it, what gives?

the only thing I know for sure happened when I pulled the engine was that the main power relay got smashed somehow, however I replaced it with a known working one so I dont suspect that to be the issue. How should I troubleshoot this?

[Dawskip]

Also want to update: Tried it on a windows laptop -- no luck.

[McGyver]

Is MegaSquirt powering on?

[Dawskip]

Is MegaSquirt powering on?

How would I be able to 100% confirm this? I dont want to try starting to car yet as its a fresh turbo build, i want to make sure the base map that I loaded before isn't messed up now.

[McGyver]

What MegaSquirt do you have? I would assume there are some LEDs that turn on when MegaSquirt turns on, are these on?

Here's a thread with what might be a similar problem. The issue was a bad ground on the wire harness Pin 2.
https://www.r3vlimited.com/board/for...not-connecting

Assuming you have a DIY PNP, I would start by checking that your 55-Pin connector has continuity to ground on Pins 2, 14, 19, & 24. If that works, turn the key and verify power on connector pin 27. If that works, either ground Pin 36 or jumper your main relay, then check for power on pin 37.

If you don't have a ground on Pin 2, try jumpering a good ground to pin 2, then seeing if it works.

[Dawskip]

Getting power everywhere I should be and getting ground everywhere I should be — at a loss right now.

[nando]

Do you have a Stim? It makes diagnosing issues much simpler. It's probably not the megasquirt, but if it is, that would tell you for sure.

[Dawskip]

Do you have a Stim? It makes diagnosing issues much simpler. It's probably not the megasquirt, but if it is, that would tell you for sure.

I do not. I did get it to connect to my computer, however it is only when the keys are out and the car is off.

before it was normal, key on I could connect, funky stuff is happening

[nando]

sounds like a relay issue. Did you modify the relay or build a start circuit? it could have gotten messed up when you broke the relay, or if the relay is modified, the replacement could need it too.

[Dawskip]

Want to get a clear update on the situation for everyone:

at the moment, I am able to connect to the ecu — only with the car off and the key out. I loaded a base tune on it, it works. However, once I turn the key on the lights in the ecu go out, and I’m no longer able to connect.

i get power on ecu pins 36/37 and 27. It has continuity to ground on Pins 2, 14, 19, & 24.

on the main relay, I’m getting a constant 12v from pins 30 and 86.

[Dawskip]

Got everything else hooked up, went to crank, and got no spark.

I tried to test for continuity on pins 7 and 15 and got nothing.

[Dawskip]

sounds like a relay issue. Did you modify the relay or build a start circuit? it could have gotten messed up when you broke the relay, or if the relay is modified, the replacement could need it too.

Is there a way to test the wiring for the relay to confirm that it is setup correctly? The previous owner did wire in a switch to start the car rather than the key (still have to turn it however).