DTC clearing after each upload

[mike_99gsx]

I do not know if this is unique to my 2026 DE5. But every time I upload a cal file, I have to run the diagnostics, clear the DTCs, and then the CEL goes off, rev match works etc.... No big deal when the laptop is in the car.

But tonight I was trying out the idea of using the Flashpro to send the primary vs secondary files to the ECU (no laptop). This also works fine. However, the DTCs are there after the upload just like they would be using the laptop.

SO I think I know the answer but is there any way around this? It sort of defeats the purpose of not needing the laptop for an upload if I still have to clear the DTCs after the flashpro sends the cal.

Thanks!

[Hondata]

You should not need to clear DTCs after an upload. What DTCs do you get?

[mike_99gsx]

Thanks for getting back to me. I get an emissions light on the dash along with the rev hang. Herr is a pic of the actual DTCs after each upload.

[Hondata]

There's no ECU related DTCs. The rest almost certainly are network related DTCs from other modules and do not matter. If there are ECU related DTCs then chase those down, otherwise they should clear in a short driving cycle.

[mike_99gsx]

So I have had time to drive the car around more after your advice and here is what I have found.

1.) It does indeed clear on its own and I wasn't being patient enough

2.) I have uploaded and tried 3 different times. Each time has taken between 15-25 miles.

3.) The code has never cleared in the middle of driving. It has just cleared after an ignition cycle.

4.) Ignition cycles have ranged anywhere from 4-10 during these miles. So I really do not know if there is a correlation between cycles vs miles driven.


So I am glad I now know that it will eventually clear. But I was really hoping I would be able to push the primary vs secondary calibration at the track without getting the laptop out. But I guess it isn't a huge deal. But I don't want to deal with seeing the CEL on the dash, rev match disabled etc while starting a session on the track.

[Hondata]

None of those DTCs should cause the check engine light to go on. They should all be network DTCs from reflashing.

Some 'permanent' DTCs cannot be cleared and generally require three driving cycles without an error before they self-clear.

[blk.de5]

My 2026 DE5 does the exact same thing after every upload. I end up having to use a different scanner that I keep handy to clear the DTCs. I get codes for the BCM, LKAS, push-to-start, and a few others. The car seems to run fine once they're cleared though. Have not tried waiting a few ignition cycles.