What does it mean?
B2543 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Right Head Lamp (Low Beam) Short to Ground .
Symptoms
- Right low beam does not illuminate at all
- Fuse blows repeatedly or the module cuts the light out a few seconds after switch-on
- Automatic headlamp function may disable both low beams as a protective measure
- Lighting fault message displayed in the cluster
- Right side of the road is poorly lit, with obvious asymmetry in the beam pattern
- On discharge systems the lamp may flash once and go out
Likely causes
- Failed low beam bulb that has shorted internally rather than simply burning out
- Corroded right headlamp connector with the feed terminal arcing to the housing or bracket
- Damaged ballast or LED driver module in the right lamp assembly on vehicles with discharge or LED lighting
- Wiring pinched between the headlamp assembly and the body during a previous headlamp or radiator support repair
- Chafed harness under the right inner fender or behind the wheel arch liner
- Water tracking into the lamp housing through a cracked lens or missing rear cover seal
- Internal short in the lighting control module or the smart junction box output
How to fix it
- Verify the fuse and check whether it blows again with the headlamp connector unplugged
- Inspect the right headlamp connector and its terminals for burning, corrosion or a pushed-back pin
- Measure resistance from the low beam feed to ground on the harness side; a near-zero reading means a shorted wire
- On discharge or LED lamps, unplug the ballast or driver module and retest to see whether the short lives inside the assembly
- Check for water inside the lamp housing and confirm the rear cap and lens seals are intact
- Inspect the harness routing between the lamp, the radiator support and the inner fender for pinch and chafe damage
- Repair the wiring or replace the failed lamp component, then command the output with a scan tool to confirm the fix