Code Definition

B2506 — LF LAMP HIGH BEAM CIRCUIT Short to Battery

System: Body  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About B2506

B2506 is a generic (obd-ii standard) body diagnostic trouble code. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B2506 is stored, the module has detected a short-circuit (voltage pulled to ground or to supply) in the monitored circuit; and a signal or supply voltage higher than the expected operating range.

Scanning & clearing: Body (B) codes are often stored in the body control module, airbag module, or climate module. A basic OBD-II tool usually will not read body codes — an enhanced or OEM-level scan tool is typically required.

Because B2506 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The Body Control Module (BCM) or front lighting module controls the left front high beam headlamp by switching battery voltage or ground to the bulb. DTC B2506 is set when the BCM detects that the left front high beam control line is shorted to battery voltage, meaning the wire is held at or near system voltage while the BCM is commanding the output OFF. The BCM monitors feedback on its output line to confirm its own driver state; finding battery voltage on the line at the wrong time tells the BCM that an external source is feeding the circuit, so the driver is disabled to protect itself and t...

Join TaT to view the complete code information and diagnostic details.

Quick Facts