Body
Generic/SAE
OBD-II Fault Code
B2452: Aux Heater Fuel Pump Circuit Open
Meaning, symptoms, likely causes, diagnostic checks and repair guidance for B2452.
Fuel system
Use this category to narrow your checks before replacing parts.
High
Severity is a general guide. Confirm with scan-tool data and vehicle symptoms.
What B2452 usually means
Aux Heater Fuel Pump Circuit Open.
Common symptoms
Body/accessory warning lamp or feature not working; Hard start, hesitation, stalling or inaccurate fuel reading depending on component
Likely causes
Low fuel pressure; Faulty pump/regulator/sensor; Wiring fault; Clogged filter; Injector fault; Open circuit; Disconnected connector; Broken wire; Failed component
Diagnostic checks
Check related fuses, connectors, grounds and switch/module power supply; Check fuel pressure and sensor data; Inspect pump/injector fuses, relay, wiring and grounds; Check connector fitment and continuity from module to component
Repair guidance
Repair wiring/relay issues, replace clogged filter, failed pump/sensor/injector only after testing; Repair open wire/connector or replace the failed component after continuity test
Verification after repair
Operate the affected body/accessory system and rescan