Hi,

I'd like to drive the tach directly from the tach output pin on the Toyota COPs, has anyone done this before on an NB? My motivation is to free up an output on the ECU.

I am assuming it needs a pullup circuit, although I am unsure as to how many of the COPs need to be connected to the circuit for it to generate the correct signal to suit the NB tach?

Cheers

 

bring it into the diag box.

 

Can I just feed the signal directly into 2K on the factory loom?

I'm suspecting I have to wire two of the 4 up to get the correct signal for the NB tach?

 

You need to connect all four wires together, then a 1K pullup to 12V and finally connect it to 2K as you said. I've tried it on a 03 and it works.

 

? The NB ECU generates the signal for the tach.

 

Only 2 need to be connected if wasted spark, or all 4 if sequential.

 

In my case, I connected all four and it worked?

 

Awesome, exactly what I was after!

Yep, and thanks to your alternator circuit the NB ECU will be sitting in my shed!

I'll be running both sequential spark and fuel, so I'll just hook them all up. The bit that had me wondering was the aftermarket ECU (Adaptronic) the current tach output is set to '50% DC' of ignition and it works fine.

I really wish I had a scope!

Thanks guys