Left Headlight Stays On After Locking - 2017 E-Class Estate

[Oobals]

I've finally replaced the left SAM headlamp controller (A2139005711) and successfully resolved the issue of the left headlight turning on a few minutes after the car is locked. Note the replacement unit did not require coding, it was plug and play.

I inspected the headlight for cr@cks and the SAM unit for water or moisture ingress. Both were completely dry, as shown in the attached image. However, since the SAM unit has been replaced before, I'm wondering if there might be a condensation problem, especially considering the slight condensation I noticed on the lower part of the headlight when the issue occurred. If the issue persists, I'll replace both the headlight and SAM unit, only time will tell.

Given that the SAM module controls the static LED dipped, main beam, side light, and indicator, it's an incredibly complex component and may experience reliability issues in the future with these designs.

 

[bigchevy66]

FYI: This is not called a SAM. It is one of the headlight control units (some headlights have multiple control units attached to the headlight for different headlight options and functions). Also, you can clearly see the water damage to this control unit, so unless you replace the headlight unit, it will happen again.

 

[Oobals]

Thanks for the update, you are right, it will most likely happen again so next time I will have to replace the headlight.