U0543Invalid Data Received From Headlamp Control Module B
- Generic OBD-II code · Network
- How the car detects it
- Headlamp control module B is the second light controller, usually serving the headlamp opposite module A. Bentley's 2019-2020 Continental GT campaign (2056293/1) handles the two as light control left and right, at diagnostic addresses 29 and 39, and both needed new software when the outer daytime running lights failed. Jaguar's 2020 XE likewise names HCMA and HCMB (SSM74402). Which side B covers remains vehicle-specific. No public manufacturer text uses U0543; it marks data from B reaching the network in a form the receiver cannot accept. Matrix or bending light then normally falls back to a fixed low beam on the affected side, and a lighting warning appears. Swapping a headlamp without coding or running mismatched software levels left and right are typical triggers. U0242 means B is silent; A is U0542.
- What you may notice
- Lighting system warning in the cluster
- Matrix or bending light on one side fixed to low beam
- Daytime running light on one side out
- Likely causes
- LikelyDifferent or outdated software in headlamp module B compared with A
- PossibleHeadlamp B replaced without coding
- RareInternal fault in headlamp module B
- Repair
- Medium · Usually a job for a workshop.Typical cost: €0 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.