Code Definition

B2249 — Head Lamp Relay Coil Short to Battery

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

About B2249

B2249 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 B2249 is stored, the module has detected a short-circuit (voltage pulled to ground or to supply) in the monitored circuit.

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 B2249 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) controls the head lamp relay by switching the relay coil low side to ground, which energises the relay and supplies battery voltage to the headlamp circuits. DTC B2249 is set when the BCM detects battery voltage on the head lamp relay coil control wire when the relay should be off, indicating a short to battery condition in the coil control circuit. The BCM uses an internal pull down driver and continuously monitors the control wire for feedback to verify proper relay operation. When this code is set, the head lamps may remain on continuously regardless of the swi...

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