Race-Spec Flex Fuel Wiring and Sensor Kit for KPRO v4


First, review HONDATA’s help file for setup info here:



Digital Input Wiring



We provide you ONE single wire that you will need to hookup to a fused, switched 12 volt (battery) source.  Other than this wire, the kit is plug and play.  I would recommend splicing into the ECU power supply (12v) at pin A2 or A3. 


Flex Sensor Subharness

  1. Power (Red/Black) – 12 volt
  2. Ground (Black)
  3. Signal (White) – to KPRO Board


You are responsible for your own fuel line plumbing.  We recommend the sensor be placed into the feed, after the fuel rail but before the fuel pressure regulator in a “return style” fuel system.  You can place the sensor inline on the fuel return if needed, but this is not our preferred location.  For a returnless system, the sensor must be on the feed, before the fuel rail.


Wire Color Updates - 5/31/18

Wire Color Updates - 8/31/20

Revision 03/30/22 – Simplified Wiring to ONLY Flex Input.  Removed VSS and CAN.