DIYPNP MS2Extra - Stalling due to Sync Loss Reason 39, CAS signal
 

Nope.

Nope.

Sync loss 39's in my car were bad coils and a bad CAS. Both were causing Sync 39's and was a bitch to figure out.
No idea if your using COPS or not.

Nope.

Are the pull-ups wired to 12V or 5V? Try opposite of whatever you have and see if it makes a difference. I have MS3 and an 01 engine but I would get sync losses with my pull ups wired to 12V and they completely disappeared when I put them to 5v.

I would have guessed this to be a ground problem but you said you covered that. And on the voltage spikes, while they may be present I don't know that it would affect the ecu. It should have a voltage regulator that can handle that or the ecu would be toast in no time.

Edit: and you can try different resistors for the pull ups instead of just the 1K ohm recommended. I know it's a proven installation but not every car is going to be identical for one reason or another.

Nope.

Nope.

Nope.

Any luck

I have a similar problem but only became more notorius when i turn on boost control.
check the video from second 50 to 60 the compose log is like yours...

https://www.miataturbo.net/megasquir...-signal-92626/

what model year?

pics of how you built the MS please.

hi there

My MS is a DIYPNP 1.5 and my miata is 1.8 1996

I don't I don't see the pictures

https://cimg5.ibsrv.net/gimg/www.mia...ae7f7c43ab.jpg
https://cimg7.ibsrv.net/gimg/www.mia...96442b3672.jpg
https://cimg8.ibsrv.net/gimg/www.mia...5da158a017.jpg
https://cimg9.ibsrv.net/gimg/www.mia...b9894f4609.jpg

Sorry for the size...

I notice that there is missing R14 2.2K 1/4W resistor
on the board it connects to vref

Edit
ok r14 is because AC