Thanks to everyone for chiming in here. Some interesting info from @StealthHawk
I've narrowed down my problem a lot now :
- First thing I did was retest voltage coming up from the KL harness (just before the PWM) : good. I had a low number the other day on that side (11.3V) but I now think it was because I had been running lights on battery for a few minutes before I took out the multimeter. So anyway, good voltage coming up from the passenger side circuit. But no light.
- Next I took the passenger side xenon bulb out and connected a halogen bulb into KL harness : light.
- Next, remove driver side bulb and connect it on the passenger side : light.
- Final step : connect passenger side bulb on driver side : no light.
So I've narrowed it down to... a bulb issue. But... is the bulb really bad ? I thought dying xenons changed color gradually and let you know they were failing quite some time in advance. Mine (passenger side) was intermittent for weeks : sometimes it fired, sometimes it didn't. When it fired, it fired normally with its usual color and intensity.
I never saw it flicker or fail while I was driving. When it didn't work, it just wouldn't fire when I turned the headlights On (I don't use Auto headlights), and once or twice I got it to fire up while driving just by turning the headlights Off and On again, but only a few times.
Almost sounds like how a broken incandescent bulb filament sometimes behaves for a short period of time : sometimes the ends come together and you have light, and then they separate and no light, until the thing just falls apart. But xenons aren't built like that... so I don't know what to think. Can a xenon bulb vary its impedance with age ? If so, could that be enough to trip the BCM because of an abnormal load ? My lights were installed in January 2017 and they don't have much On time. Oh and I turned off the features that fire up the headlights with remote start and remote door unlock, so I've been very gentle with them...
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2015 North (Canada) - V6 - AD1
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