What it means
The fuel tank pressure sensor signal is below the expected minimum voltage. Often caused by a failed sensor or a short to ground in the signal line.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The fuel-tank pressure sensor converts EVAP tank pressure changes into an electrical signal for the control module. P0452 sets when that signal falls below the expected range, which can result from a signal wire shorted to ground, a failed sensor, or a circuit fault.
Common causes
Most likely first.
- Fuel tank pressure sensor failure
- Signal wire shorted to ground
- Open or damaged wiring
- Corroded or loose connector
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
How to diagnose it
- Check freeze-frame and live sensor data to confirm that the tank-pressure signal is low and note when the fault occurred.
- Inspect the pressure sensor connector and harness for corrosion, loose terminals, damaged insulation, or wiring trapped against the body or tank.
- Check the sensor's power or reference and ground circuits using the vehicle wiring diagram and manufacturer's specifications.
- Test the signal wire for a short to ground or an open, isolating the circuit as directed by the manufacturer.
- If the wiring and connections are sound, test the tank-pressure sensor and replace it only if it fails the specified checks.
Common fixes
- Repair a signal wire shorted to ground or an open in the sensor circuit.
- Clean and secure corroded or loose pressure-sensor connector terminals.
- Replace the fuel-tank pressure sensor if its output remains below specification with a sound circuit.
- Repair a control-module fault only if the sensor and wiring test correctly.
Can I keep driving?
The vehicle is generally driveable if it runs normally, but EVAP leak detection may not work and an emissions inspection may fail. Do not ignore a strong fuel smell or visible fuel leakage.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.