P0453 — fuel tank pressure input high: test for open circuit

P0453 means the EVAP/tank pressure sensor A signal is electrically above its permitted range; it does not automatically mean physical tank overpressure, a bad filler cap or a vapor leak. Ford's 2004 FTP monitor labels P0453 as an open circuit, in contrast to P0452 (short), but bias and voltage interpretation vary by application. Follow the vehicle-specific wiring diagram and sensor transfer function.

Affected system: Powertrain

Symptoms

• MIL, possible incomplete EVAP readiness and an implausibly high or fixed FTP reading.
• The vehicle may drive normally; significant gasoline odor or leakage requires separate assessment.
• Additional input-circuit DTCs may occur if sensors share supply or ground.

Possible causes

• Open signal, backed-out terminal or unplugged connector in high-bias circuits.
• Short to reference/power or incorrect reference/ground, depending on the factory topology.
• Failed FTP transducer or cracked harness near the fuel tank.
• Controller input defect only after the wiring, supplies and sensor are proven sound.

What to check

• 1. Record freeze-frame, shared-reference DTCs and FTP data; separate electrical P0453 from leak codes P0455/P0456.
• 2. Identify the A sensor type and location from OEM information; it may be integrated rather than a stand-alone part.
• 3. Under the allowed key-on/engine-off condition, an FTP reading stuck at its upper limit suggests an input fault, not proven high physical pressure.
• 4. With power off, inspect terminal fit, continuity path and abrasion; an unplugged connector or open lead directly fits the documented Ford monitor example.
• 5. Measure feed, ground and signal at OEM-specified points. A mismatch between sensor and ECU identifies a harness/connector path; matching excessive levels require checking sensor and input bias.
• 6. Where the OEM permits isolation, compare the sensor-unplugged response with its documented expectation; no expected change suggests wiring/module, not automatic sensor replacement.
• 7. Resolve the electrical fault before physical EVAP leak testing. Smoke testing or pressure work requires approved fuel-vapor equipment and the OEM method.
• 8. After repairing a proven fault, confirm responsive signal and the applicable monitor. Recurrence calls for checking the connection under fault conditions.

Also written as: P0453-00, P045300, PO453 (some scan tools add the fault-type byte, e.g. -00).