P0453: Evaporative Emission System Pressure Sensor/Switch High Input

What does P0453 mean?

The fuel-tank pressure feedback voltage is above its allowed range. The cause may be an open return or a short to power, although real abnormal tank pressure must be considered if electrical checks pass.

Generic OBD-II definition: Evaporative Emission System Pressure Sensor/Switch High Input. Confirm applicability in your vehicle service information.

Common causes

• Signal shorted to supply voltage
• Open return or poor tank-pressure connector
• Failed sensor
• Restricted vapor plumbing causing abnormal pressure

Symptoms

• Steady check engine light
• Often no noticeable driving change
• EVAP readiness may not complete

Diagnostic focus

High input is a voltage classification, not a universal statement that the tank is overpressurized. Different sensors map pressure to voltage differently, so consult the vehicle chart.

Can I keep driving with P0453?

Severity: Low With normal running and no fuel smell or leakage, arrange an emissions-system check. If you smell strong fuel vapor or see a leak, stop safely and have it inspected; keep ignition sources away.

If the check engine light is flashing or the car runs badly, stop driving and have it checked.

Typical fixes

• Inspect the signal and return circuit
• Compare the vented pressure reading with specification
• Check vapor-line restrictions if the sensor signal is electrically valid

Sources & review

• OBD-Codes.com: P0453
• TroubleCodes.net: generic code definitions

Definitions and diagnostic background checked 2026-11-06. Generic guidance, not a substitute for the service procedure for your exact year, engine, and transmission.