I need help! Don't want to go to dealer except last resort. My 2015 Q40 failed inspection due to L headlamp and license plate lamps out. Fuses have all been checked. Replaced the HID bulb and the license bulbs. I even replaced the IPDM module (found a good one at a local junkyard) and performed the self-test. No wires eaten by squirrels. Checked voltage at the sockets - NO power. Everything else works fine, including the R headlamp. Anyone have a similar problem? Suggestions?

 

If you need it, Factory Service Manual here:
https://www.nicoclub.com/service-man...2015%2Fexl.pdf
scroll down below the viewing window and "click here to download a copy".

Man, replacing the IPDM is a drastic move and amazing you found a match (same part # and everything, right?). Running the "Auto Active Test" on page 27 of that FSM tests a bunch of things. Is that the "self-test" you tried? And still no L headlamp or license plate lights? L&R headlamps have separate fuses in the IPDM: #53 for L & #54 for R. Swap those fuses to be sure?

Fuse #52 send power to the tail lamp (running lights) and rear side markers - after a relay. If those light up but your license plate does not then it points to those specific bulbs (which may be incandescent) or the 2 wires running to them. Fuse #51 sends to the front side markers and parking lamps in the Headlight assembly and that is after the same relay, so if those work but the rears don't then look at #52. If they aren't working either then look at that relay.

Your two issues may be unrelated too, which I know doesn't help... Keep tracing and you'll figure it out.

 

Thanks for the manual link. I'll try replacing the relay, then dig into the wiring diagram.