ECU RPM signal source

[iceman]

Hi, I have a Link Storm G4+ wire in, provisionally running a 6.0L LS V8 with 4L65E auto transmission. The trans is being run with an older HGM Compushift 2 standalone TCU with wire in harness.

The TCU obviously requires an accurate RPM input which I was providing with a "Tach" signal aux tap before I realised my mistake in that that signal was also being recalibrated to get the actual cluster tach gauge to read correctly. In this particular case the RPM signal displayed on the TCU screen was low.

I'm missing something here because I can't think of any other way to obtain a "clean" external RPM signal for the TCU. Can you suggest a work around?

Cheers, Pete.

[Adamw]

You can send RPM to the controller via CAN, or you could use an aux output set to GP PWM to generate a conventional tacho signal.