Code Definition

B2449 — Aux Heater Glow Plug Circuit Short to Ground

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

About B2449

B2449 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 B2449 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 lower 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 B2449 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 B2449 code indicates that the auxiliary heater control module has detected a short to ground on the glow plug ignition circuit. Auxiliary heaters such as Webasto or Eberspacher units are independent fuel fired cabin heaters commonly fitted to diesel vehicles in cold climates to provide rapid cabin warmth and engine pre warming without idling the main engine. The glow plug inside the auxiliary heater is used to ignite the atomised diesel fuel inside the combustion chamber of the heater during start up. The control module drives the glow plug through a high side or low side switch and monito...

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