I was under the impression that PIN 53 on a CA18DET ECU is the wire from the cluster that gives the ECU it's speed info, as the box talks directly to the cluster then the cluster to the ECU (cutting this wire disables the speed limiter).
When testing this with a multimeter, with the car idling it fluctuates between .2 and 5.2 or so volts.
When in gear and at speeds from 0-100km/h the output is almost 2.6-2.8V which means it's not a straight voltage signal being used.
The Apexi RSM taps this wire for its speed info also, but what is it doing with it?
Is this actually a pulsed signal?
Edited by ActionDan, 16 October 2017 - 08:07 PM.