P1445

Ford

Purge Flow Sensor Circuit High Input

Definition source: Manufacturer reference catalog
Definition verification: Not independently verified for display.
Time: Varies by diagnosis and vehicle | Diagnostic difficulty: Medium
Medium Severity

The powertrain control module has detected a higher-than-expected electrical input from the purge flow sensor circuit. The sensor provides information about purge flow in the evaporative emissions system, which the module uses to monitor fuel-vapor purging. This code identifies a circuit condition, not proof that the sensor itself has failed. Emissions performance may be affected, and drivability symptoms are possible depending on the vehicle and the fault.

Report an error with this code

⚠️ Before You Begin (Safety First)

This code alone does not usually mean the vehicle must be stopped immediately. Stop driving if the engine runs severely poorly, stalls in traffic, or you notice a strong fuel odor or a fuel leak. Have a fuel leak checked promptly.

Common Symptoms

  • The check-engine light may be on; a warning light may be the only noticeable symptom.
  • The vehicle may fail an emissions inspection if the fault affects evaporative-emissions monitoring or performance.
  • Rough running, hesitation, or stalling may occur if the underlying fault also disrupts purge operation; these symptoms are not guaranteed by the code.
  • A fuel-vapor odor may occur if there is a separate or related evaporative-emissions problem, but the code alone does not establish a leak.

Common Causes

  • A failed purge flow sensor may produce a circuit signal that reads high.
  • Damaged wiring or a connector problem may bias the sensor signal high.
  • A signal wire shorted to voltage, or a poor sensor ground or connection, may cause a high input reading, depending on the circuit design.
  • A fault elsewhere in the circuit or, less commonly, in the control module may produce the same detected condition.

Diagnostic Steps

  1. Record the code and any related codes before clearing them; other codes may help identify whether the problem involves the sensor circuit or a broader emissions issue.
  2. With the engine off, visually inspect accessible sensor wiring and connectors for loose plugs, corrosion, chafing, or heat damage. Do not pull on wires or probe terminals with unsuitable tools.
  3. Check the vehicle-specific owner information for the correct component identification and any safety cautions before attempting further checks.
  4. If the wiring or connector appears damaged, or the code returns, arrange model-, year-, and engine-specific electrical diagnosis rather than replacing the sensor based on the code alone.

When to Call a Professional

Confirm the code and check for related codes and available scan data before replacing parts. Inspect the purge flow sensor connector and wiring for damage, corrosion, loose connections, or signs of a short. A technician can compare the sensor signal with the circuit’s power and ground, test wiring continuity and shorts using model-specific service information, and determine whether the sensor, wiring, or another circuit component is responsible.

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Commonly Asked Questions

Does P1445 prove the purge flow sensor is bad?

No. It reports a high input in the sensor circuit. A wiring, connector, ground, or other circuit fault can produce the same condition.

What does the purge flow sensor do?

It provides information about purge flow in the evaporative emissions system so the control module can monitor fuel-vapor purging. The exact system design depends on the vehicle.

Can I keep driving with P1445?

Often the code alone does not require immediate shutdown, but have it diagnosed. Stop if the vehicle stalls or runs severely poorly, or if you detect a strong fuel odor or leak.

Why does the code say high input?

The control module is detecting a sensor-circuit signal higher than expected. The cause must be isolated with vehicle-specific circuit testing; the code does not identify which part has failed.

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