Code Definition

B2454 — Aux Heater Blower Fan Circuit Open

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

About B2454

B2454 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 B2454 is stored, the module has detected an open (broken or disconnected) electrical path 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 B2454 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 auxiliary heater blower fan is a small DC motor inside the auxiliary heater unit that draws combustion air into the burn chamber and, on air style heaters, also moves heated air to the cabin. The auxiliary heater control module varies blower speed during the startup, combustion, and post purge phases by commanding the motor through a low side or PWM driver, and it monitors the supply line voltage to confirm the motor load is present. DTC B2454 is set when the controller detects an open circuit in the blower fan supply, meaning no current flows when the motor is commanded on and the driver ...

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

Quick Facts