P0453: Evaporative Emission System Pressure Sensor/Switch High
The fuel tank pressure sensor signal is higher than the computer allows, as if the tank were under too much pressure.
What P0453 means
P0453 is the high side partner of P0452. RepairPal explains that the EVAP pressure sensor is indicating pressure values above specification. A high signal can be electrical, such as the signal wire shorted to voltage or a broken ground that lets the signal float up, or a failed sensor. It can also be real pressure: if the vent valve or vent hose is blocked, the tank cannot breathe and pressure builds, especially on hot days. A loud hiss when removing the gas cap or trouble filling the tank are hints that the vent side is blocked. Overfilling the tank can also push liquid fuel into the vapor lines and damage the canister. Shops check the reading with the gas cap off. If it still reads high, the sensor or wiring is at fault. If it reads normal with the cap off but climbs when sealed, they look at the vent valve and canister. Fixing it keeps the EVAP monitor working.
Common symptoms
- Check engine light on
- No change in driveability
- Hiss of pressure when opening the gas cap
- Trouble filling the tank
- Failed readiness test
Most common causes
- Faulty fuel tank pressure sensor
- Signal wire shorted to voltage
- Open ground at the sensor
- Blocked vent valve or vent hose causing real pressure
- Overfilled tank with liquid fuel in the vapor lines
What to check yourself first
With the engine off, remove the gas cap and check the scan tool reading; it should drop to about zero. Check the vent hose and filter near the canister for mud or debris. Avoid topping off the tank.
Typical fixes and what they cost
| Fix | Typical cost | Note |
|---|---|---|
| Replace fuel tank pressure sensor | $356-$457 | When the sensor reads high with good wiring. |
| Electrical diagnosis to find a wiring or connector fault | $122-$179 | For a short to voltage or open ground. |
| Replace EVAP canister (includes vent valve on many cars) | $558-$643 | If a blocked vent valve or canister is trapping pressure. |
Typical US price ranges for parts and labor, not quotes. Your shop should confirm the cause with a diagnostic before replacing parts.
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Related codes
- P0451 Evaporative Emission System Pressure Sensor/Switch Range/Performance
- P0452 Evaporative Emission System Pressure Sensor/Switch Low
- P0446 Evaporative Emission System Vent Control Circuit
- P0449 Evaporative Emission System Vent Valve/Solenoid Circuit
- P0455 Evaporative Emission System Leak Detected (large leak)