B0240: Headlamp Switch Circuit
Standardized SAE J2012 code · B02xx codes
What does B0240 mean?
The body control module has detected an implausible state at the headlamp switch — for example simultaneous low and high beam request, or no signal at all. Lighting functions may be erratic.
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
Symptoms
- Warning light or symbol related to the affected system
- Comfort or safety function impaired
Common causes
- High Headlamp switch worn or failed
- Medium Wiring or connector fault
Likelihood is a general estimate across vehicles; your make and model may differ.
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