Volvo XC90 adaptive headlight malfunction - Right

forumoto · Post by **forumoto** » 24 Apr 2025, 03:51

I have a problem with Volvo XC90 adaptive headlight.
First of all, headlamps work fine (high beam, low beam and turn signal).
Also, when I start the car, right adaptive lamp does not move up and down and right and left (left lamp does this thing after a startup) and i get an adaptive headlamp malfunction
error in the dashboard. When I turn the steering wheel - the lamps do not run to the turning location
Diagnostic shows this - CEM -U132382 adaptive headlamp module right.
I have removed a working lamp complete and plug on the front right but still U error shows still. I also removed the headlamp control unit AHM and install it on the left headlamp and
the error do not show up at the left side. Now i scoped the LIN bus line of right headlamp and i compare it to the left, everything is fine and the signal square wave is same. cem
update was also done but yet still the error is there, please if someone solve this thing some before, help. thanks

Vova585 · Post by **Vova585** » 24 Apr 2025, 17:17

Can you please clarify if the right headlight was functioning correctly when plugged into the left side? I would suspect that the problem would be inside the unit itself. It is likely has 2 electric motors which turn the light inside. Most likely they used some plastic gears which either broke or stuck. Unfortunately as far as I know, they are "sealed" units where you can't repair them easily. I would look if anyone around you offers Profesional headlight repair where with ultrasonic knife or heat they can open the unit and inspect the motors and leveling sensor(if I am correct there should be a position sensor inside). Usually volvo would say replace entire unit. Good luck.

forumoto · Post by **forumoto** » 24 Apr 2025, 19:48

Solved - I got this solved by going after the engine fuse box after extensive check and realize a power is not coming to to the one side of the headlamp socket, and it was fuse 48. someone pulls it out from it position and leave that side empty. so when i put another fuse there, the error code went away and everything is fine for front right side.. thanks

forumoto · Post by **forumoto** » 24 Apr 2025, 19:50

Vova585 wrote: ↑24 Apr 2025, 17:17 Can you please clarify if the right headlight was functioning correctly when plugged into the left side? I would suspect that the problem would be inside the unit itself. It is likely has 2 electric motors which turn the light inside. Most likely they used some plastic gears which either broke or stuck. Unfortunately as far as I know, they are "sealed" units where you can't repair them easily. I would look if anyone around you offers Profesional headlight repair where with ultrasonic knife or heat they can open the unit and inspect the motors and leveling sensor(if I am correct there should be a position sensor inside). Usually volvo would say replace entire unit. Good luck.

thanks for commenting, i am happy at least you have drop a line of suggestions that should be look at,

Vova585 · Post by **Vova585** » 24 Apr 2025, 21:44

forumoto wrote: ↑24 Apr 2025, 19:48 Solved - I got this solved by going after the engine fuse box after extensive check and realize a power is not coming to to the one side of the headlamp socket, and it was fuse 48. someone pulls it out from it position and leave that side empty. so when i put another fuse there, the error code went away and everything is fine for front right side.. thanks

Thank you for update. Given advanced level diagnostic you performed with scoping the signal wires I almost assume all powers and grounds were checked so was not even thinking to suggest it. At the end of the day so happy for you for not having to spend $1000+ for a headlight. Good catch.