Hondata

I would recommend trying this in a known working vehicle to see if it works there without issues.


I don't have a working kpro vehicle to try it with.

I am almost certain it's something alternator related. Unplugging the 4 pin connector on the back of the alternator, everything works perfectly ...

Changing the alternator didn't fix it. Same problem.

I'm a bit lost about what else I can check at this point. All connections seem solid.

Check the sensors themselves and the wiring in any junctions as it may be vibration related if it is at high RPM.

Are you using resistor or non-resistor type spark plugs?


So a bit of troubleshooting more. Unplugging the alternator makes the issue go away. I'm going to swap in another ...

Check the sensors themselves and the wiring in any junctions as it may be vibration related if it is at high RPM.

Are you using resistor or non-resistor type spark plugs?


NGK BKR8-EIX for the plugs

I'm just confused why the ECU would read a pin is being grounded when it's not connected to ...

Spunkster wrote: Tue Feb 24, 2026 4:36 pm This is most likely wiring related as most aftermarket harnesses do not have the shielding that an OEM harness has.

I've swapped back in the OEM loom and I'm back up and running again. Unfortunately the inputs are still doing the same thing and flickering at high RPM. Any idea what to check next?

Spunkster wrote: Tue Feb 24, 2026 4:36 pm This is most likely wiring related as most aftermarket harnesses do not have the shielding that an OEM harness has.

I'll swap it for an OE loom and see if the problem goes away then report back.

Spunkster wrote: Tue Feb 24, 2026 10:13 am Have you tried your ECU on a known working vehicle using their calibration?

I don't have access to any other working vehicles that run kpro.

Are there any other troubleshooting steps you can recommend I can take other than what I've done already?

Good Afternoon

When posting a KPro problem with your vehicle, please include:
- what vehicle you have - Toyota MR2 swapped with a K20A2 Turbo.
- serial number of your K-Pro - 69166
- version of software being used (from Help, About) - Hondata K-Series Programmable ECU Editor (32 bit)
- ECU part ...