Code Definition

B2452 — Aux Heater Fuel Pump Circuit Open

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

About B2452

B2452 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 B2452 is stored, the module has detected an open (broken or disconnected) electrical path 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 B2452 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 fuel pump is part of the fuel fired cabin and coolant preheating system fitted to many diesel vehicles operating in cold climates, typically a Webasto or Eberspächer style dosing pump that delivers small precise fuel pulses into a combustion chamber where the fuel is burned to warm a coolant heat exchanger. The auxiliary heater control module drives the pump with low duty cycle solenoid pulses and continuously monitors the driver line voltage to confirm the load is present. DTC B2452 is set when the controller detects an open circuit in the dosing pump driver line, meanin...

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

Quick Facts