Left headlight LED channel 7 and 8 error - blinker fails

[volver]

I have a weird problem in 2019 S60 U.S. version. I installed EU headlights (used, from different cars  but same version), changed the config to ROW Type B, and that handled pretty much all the issues with led channel 4 error (side markers missing) etc.
But on HCML there are still persistent error for channel 7 and 8 (signal too low or smth). And after clearing HCML DTCs (errors actually do not clear) blinker works fine, but after first car restart blinker shows up as malfunctioning. It blinks one time and then stops blinking.
After resetting HCML (errors do not clear), again works fine until restart or sometimes two.
When comparing voltages on HCML and HCMR (assembly codes seem the same) on channel 7 and 8 and other things, everything seems the same.
Anyone has ideas? I was thinking - perhaps I can reflash the HCML with modified firmware to ignore some resistance fluctuations or smth but idk. How to diagnose what is wrong. Especially if blinker mostly works.

[IMAY2023]

If you used your original controllers and just replaced the headlights, you will need to update the configuration of the HCMs according to the HEX numbers and production date printed on each headlight sticker. Drop an email to support, they might have the correct software files for you.

[volver]

I bought the headlight together with HCM (they are inside headlight, right?) as is. And everything else in that headlight works fine, bending etc. Of course I cannot guarantee that the module was not replaced and never programmed correctly by previous owner.
Also, coincidentally the sticker of that headlight is missing. Can reading HCM values out with Orbit help in this case if hex numbers are not known?

Also, I found this post where somebody writes about similar problem with turn signal, so I really believe this is programming issue.
https://mhhauto.com/Thread-XC90-2019-LED...nit-coding

[IMAY2023]

Are you talking about s60 or xc90.? 
S60 has only one controller looks like this. it's not inside the headlight it's outside. 

Can reading HCM values out with Orbit help in this case if hex numbers are not known?

Not sure about that, even Orbit could read that info from the HCMs, the module would respond with the last progmened one. 
I do think it's a programming issue but you need to know the HEX values and the production date to be able to program the controllers correctly.

[Joe558]

I tried the same, with the same result. I eventually changed the settings to non-bendy to stop the errors. I haven’t found a solution.

[iamyxy]

This may be a matching issue

Correct conversion of headlight codes is required

[volver]

So I had to do a whole lot of learning and experimenting to just find out that for some reason the weak backup battery, which is located under the hood of Volvo S60 2019, was causing the weird errors in HCML about LED channels 7 and 8. Interestingly no other direct or indirect errors were seemingly caused by it, and HCMR was error-free.
Orbit Support was very helpful to me by explaining the inner workings of HCMs, and even providing updated software for those.
So thanks to everyone!

[Power6]

Hmmm this is interesting result! Thanks for sharing back. I may have only looked at a couple cases of this, but in all cases I looked at we had the correct headlight codes written, correct software etc. but yet still an issue with the LED channel DTCs.

This is not the first time, that the weak support battery, or overall low 12V battery charge level causes strange issues. For example we see when the 12V battery level is low, you may see parking assist error message on the dash and DTCs for parking sensor issues.

[R1maS]

For example we see when the 12V battery level is low, you may see parking assist error message on the dash and DTCs for parking sensor issues.

Andrew, I can confirm that not only main 12V battery can cause parking issues, but backup battery as well - I mean, no DTC with diagnostics, but message on the dashboard.

[volver]

Quick update. So - after changing backup battery, the problem (errors about LED channels 7 and 8 signal to low) soon returned. Sometimes headlight would work just fine, but mostly not. I continued diagnostics. The HCM turned out to be 100% fine. Voltage levels fine (backup battery solved other glitches). So I just swapped out the headlight. It is likely that the culprit is the the small control module within a headlight assembly itself, but I did not have time to diagnose that.