• When flashing software to an HCM (see flashing with OrBit guide), OrBit will prompt you to write the config string. You do not need to write the config string each time you flash, you can bypass it when prompted if not needed, config string write only needs to be done once when a new headlamp unit or HCM is fitted.
  
• The config string contains headlamp production info and also sets the "side" of the HCM module. Writing the config string allows you to change the side, converting the HCML to HCMR or vice versa.
  
• To write the config string, you need to read the information from the label on the headlamp unit. The config string dialog in OrBit contains instructions to enter the information from the headlight.
  

• When the HCM is installed on to the headlamp, and plugged into the car, it will respond to diagnostics as HCML or HCMR according to how it was programmed last (from the car it was removed from). 
  
• It is helpful to work on only one headlamp at a time via OrBit when installing headlamps with unknown used HCM modules. You can achieve this by only plugging in a single headlamp. When working on one headlamp, unplug the other one from the car harness. If the car is already assembled, you can pull the fuses for the opposite side headlamp to disable the HCM on that side.
  
• When you have checked and or corrected the "side" of one HCM, unplug it (or pull fuses) and plug in the other side to check and correct that module. You want to avoid trying to flash the used HCM and write the config string with duplicate HCMs in the car (2 HCMR or 2 HCML). Work on only one headlamp at a time until both sides are correct.
  
• To check the newly installed used HCM, with the "other side" headlamp unplugged, connect OrBit to the car, and determine if the used HCM responds to HCML or HCMR. 
  
• There are multiple ways do find which "side' the HCM is responding as, the easiest is to attempt to read any Data by ID (DID) from the HCML and HCMR in turn. You should get a response from only one of the modules, the other will return an error that OrBit is unable to read from the module. Now you will know which side the used HCM is programmed to.
  
• If the side is correct, for example the Left side is responding as HCML, you can proceed to flashing software to the module and write the config string.
  
• Use the "skip programming checks" checkbox on the "Experts Toolbox" tab when performing this process, to prevent OrBit flash fail due to HCML or HCMR "not responding".
  
• If the side needs to be corrected, example the Left side is responding as HCMR in the car, you will need to flash a software for the current module side, in order to change the config string and switch the side. For this example, left side is HCMR, in the ECU Flash box, choose the SBL for HCMR and choose any software for the HCMR to flash (it doesn't matter which one). Then proceed to flash and choose to write the config string, using the config info from the headlamp sticker. After flashing with the new config string, the HCM will now respond as the "correct" side, HCML or HCMR. You can then proceed to flash all correct software to the HCM.
  
• When one side is correct and complete, unplug that headlamp from the car harness, and plug the other side headlamp in.
  
• Repeat the above process to check the "side" the used HCM is responding as, and write the config string. Then proceed to load the correct software to the HCM.
  
• When both used HCMs have been checked and corrected: you have one HCML and one HCMR in the car, both headlights can be plugged in and reassemble the car.
  

• Used parts vendors always take the HCMs off and sell them separately, because they are dumb and know nothing about Volvos.
  
• Volvo builds cars with "special" parts at the factory, and by special that means cheaper ;-) The HCMs the car is built with won't support the bendy lights.
  
• You must get proper used HCMs, that support the bendy lights, in addition to the headlamps. They are not typically too pricey though.
  
• You will have no idea if the used HCMs are "left" or "right" (HCML or HCMR), or if they are loaded with software for you model, or a different model (see dumb parts vendors)
  
• You will need a way to set the used HCMs to the correct "side", unless you get lucky and get one used HCML and one used HCMR!
  
• You may need to load correct HCM software on the used HCMs
  
• You will want to "learn" the headlamp module to the HCM (not critical but should be done)
  

(09-06-2023, 02:49 PM)Power6 Wrote: I think you emailed me buddy, I am catching up after vacation, I will get to you, we need to see what modules you have but I should have the SBL for you. You do need that SBL to write the config string, as the HCM must be in programming mode to write it.

(12-24-2023, 05:08 PM)Power6 Wrote: I'm probably less familiar with VIDA process than you are ;-)  and I assume you mean MY2023+

I am pretty sure you could switch it with OrBit, using the process here. You load an HCMR software to the HCMR (mounted on the left headlamp), in the process you write the headlamp config string. After that is complete the HCM should be responding as the HCML and you can proceed to load all the HCML software.