Network, generic

U0241 Lost Communication With Headlamp Control Module A

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Headlamp control module A runs the electronic front lighting, for example beam levelling, cornering light or LED segments. Ford calls it HCM; it sits on the vehicle network and logs network faults of its own, as on the 2017 Lincoln MKZ after remote start (SSM 46508). U0241 is stored by a listener such as the body controller, cluster or gateway once the periodic frames of module A stop arriving within its timeout; no maker publishes that limit. Land Rover names U0241-00 among several U codes on the 2015 LR4, caused by a console cooler box that stays powered after switch-off and disturbs other modules, cured by reflashing the ABS unit (SSM72146). Expect a headlamp warning and adaptive functions held at a basic beam. Module B is U0242; corrupt data from A give U0542.

Likely causes

Headlamp module without power or ground (fuse, connector at the lamp)
Damaged or corroded bus wiring in the front end, often after a collision or lamp replacement
Network disturbed by another module or accessory staying awake (Land Rover cooler box)
Headlamp module software fault or internal failure

Symptoms

  • Headlamp or adaptive lighting warning in the cluster
  • Cornering, levelling or matrix functions inactive, basic low beam only
  • Several U codes in other modules at the same time

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–1,200
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

headlamp module acan bus

Related codes

U0242U0542U0181U0182

References: static.nhtsa.gov, static.nhtsa.gov, en.wikipedia.org.