View Full Version : Wrong RPM reading

23rd-June-2016, 01:20 AM

I installed MAP ECU 1 on Nissan 200SX S13, CA18DET engine - almost same wiring like SR20.

When i connect MapCal (2.1 version) it shows wrong RPM value (cca 1/10 of real value). I checked connection between engine ECU and MAP ECU, is OK. Do you have any idea where should be problem?

Thank you for response

23rd-June-2016, 12:20 PM
I can only assume the RPM signal is different on the CA18DET. Ideally you want the ignition signal unless it is COP. You can usually adjust the Cylinders setting to get RPM right but it depends on the RPM source.

24th-June-2016, 06:33 AM
The signal should be same on SR and CA, both is on 1st cylinder ignitor. If everything will be ok i measure it this weekend with osciloscope. Do you have some diagram how should the signal look?


27th-June-2016, 02:20 PM
It should be just a square wave. The input can handle 5V or 12V. If it is the 1st cylinder igniter signal it should be fine and you should be able to get the right RPM with the Cylinders settting.