U0542Invalid Data Received From Headlamp Control Module A
- Generic OBD-II code · Network
- How the car detects it
- Headlamp control modules run adaptive lighting such as swivelling, levelling, matrix segments and LED daytime lights, frequently with one module per headlamp. U0542 means a receiver, for example the body or lighting master module, gets messages from module A that fail its checks. No manufacturer publishes text for U0542. Jaguar documents the units by letter: on the 2020 XE, headlamp control modules A and B stored false low-voltage faults for position and daytime lights because current and board voltage were sampled out of phase (SSM74402), and new software with a revised threshold was announced. Bentley's Continental GT treats the left and right light controllers as separate addresses for reprogramming. Expect a headlamp warning and adaptive features held in a default position. U0241 is lost communication.
- What you may notice
- Check headlamp or lighting system warning
- Adaptive or cornering light not working on one side
- Daytime running light or position light affected
- Likely causes
- LikelyHeadlamp module A software (reprogramming released)
- PossibleHeadlamp or module replaced without coding/configuration
- RareMoisture or corrosion at the headlamp connector
- 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.