Classic car, coil input

PMU
1

Hey I’ve installed a pmu16 into an old Celica to control lights and fans and such,

I’ve got a canboard behind the dash with extra inputs from all the switches, and I’ve set up an output to trigger a light for errors, and overtemps

I have temp inputs and oil pressure to the pdm, which is easy, but I’d like a way of getting rpm, purely for a shift light but all integrated,

Obviously the factory tacho uses the coil neg, but what’s I way I can get rpm into the pdm, as shortly I’ll be adding a dash to display thems but still no ecu,

Cheers Brad.

2

Hi,
The PMU and switchboard are not able to read the frequency signal.

Possible solutions:

  1. Make a voltage signal from a frequency signal with a low-pass RC filter.
    The con is that it can have a long response time.

  2. Wheel Speed to CAN module - able to read frequency signal and send over CAN bus.

  3. If you plan to add an ADU dash, it can read the frequency signal directly.