Just for spare parts

The results of the tach experiment are in. And the winner is.....the engine computer (not me).

Hooking up the pulse generator with 5V amplitude waves to the ECM did not drive the tach. I checked at a few frequencies simulating 1000, 2000, and 4000 RPM. No go. I also checked the RPM's with the OBD scanner. This confirmed the computer was on and also confirmed zero from the RPM input.

There may be another input to the ECM that is needed (may be from the camshaft sensor). Although it would have been nice to use the OEM tach at this point it is just easier to replace the tach and speedo with aftermarket replacements.

Oh well. No big deal. Into the spare parts closet for the pulse generator. Never know when I might need one again!