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Old 07-28-2011, 09:22 PM   #1
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Default Driving the NB tach from Toyota COPs?

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
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Old 07-28-2011, 09:41 PM   #2
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bring it into the diag box.
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Old 07-28-2011, 10:07 PM   #3
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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?

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Old 07-29-2011, 03:31 AM   #4
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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.
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Old 07-29-2011, 12:29 PM   #5
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? The NB ECU generates the signal for the tach.
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Old 07-29-2011, 12:33 PM   #6
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Quote:
Originally Posted by Reverant View Post
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.
Only 2 need to be connected if wasted spark, or all 4 if sequential.
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Old 07-29-2011, 01:59 PM   #7
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In my case, I connected all four and it worked?
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Old 07-29-2011, 06:08 PM   #8
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Quote:
Originally Posted by Reverant View Post
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.
Awesome, exactly what I was after!

Quote:
Originally Posted by JasonC SBB View Post
? The NB ECU generates the signal for the tach.
Yep, and thanks to your alternator circuit the NB ECU will be sitting in my shed!

Quote:
Originally Posted by Ben View Post
Only 2 need to be connected if wasted spark, or all 4 if sequential.
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
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