Fault code P0450 – a step-by-step guide to diagnosing and fixing it

Error code P0450 is displayed and the check engine light is on - what does this mean?

DTC P0450 is set by the OBD/EOBD system when a problem is detected with the fuel tank pressure sensor or its circuitry. This fault code relates to the evaporative emission control system (EVAP) and can occur with slight variations for different manufacturers.

What can cause this fault code?

• Defective fuel tank pressure sensor
• Damaged wiring to the pressure sensor
• Corroded or loose plug connections
• Defective fuel tank vent valve
• Blocked or damaged EVAP lines
• Faulty engine control unit (ECM/PCM)
• Defective fuse in the EVAP system
• Mechanical damage to the fuel tank

What symptoms occur in parallel with fault code P0450?

• Check engine light: The check engine light lights up continuously or flashes
• Fuel smell: Smell of gasoline around the vehicle, especially when refueling
• Starting problems: Difficulty starting the engine after refueling
• Loss of power: Reduced engine power at higher speeds
• Increased fuel consumption: Noticeable increase in fuel consumption
• Fuel tank problems: Difficulty refueling or premature shutdown of the fuel nozzle

How can the problem with error code P0450 be resolved?

• Repairing trouble code P0450 requires a systematic diagnosis of the EVAP system.
• Replace the defective fuel tank pressure sensor with a new original spare part and reprogram the control unit
• Repair or replace damaged cable connections between pressure sensor and engine control unit, including insulation and connectors
• Clean all plug connections with contact spray and seal them against corrosion
• Replace the defective tank ventilation valve and check the tightness of the entire EVAP system
• Flush or replace clogged EVAP lines and check the activated carbon canister for damage
• Carry out a complete diagnosis of the engine control unit and update the software if necessary
• Check and replace defective fuses in the EVAP system circuit