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P0445 — Evap System Purge Control Valve Circuit Shorted

Generic OBD-II · all makesPowertrain (engine & transmission)

OBD-II code P0445 means the powertrain control module has detected an electrical short in the circuit that controls the evaporative emission system purge valve. This typically indicates abnormal resistance or voltage—often from a short to ground or power—that prevents the PCM from properly operating the purge solenoid.

Symptoms

What causes it — most likely first

1. Faulty purge control valve/solenoid

The valve coil can develop an internal short or suffer resistance drift, causing current draw or circuit values outside the PCM expected range and triggering a short code.

2. Wiring harness short

The control or power feed wires may chafe against the frame or another wire, creating a short to ground or power that alters circuit integrity.

3. Damaged or corroded electrical connector

Moisture intrusion, bent pins, or terminal fretting at the purge valve connector can produce unintended electrical paths that mimic a shorted solenoid.

4. Prior wiring repairs or modifications

Incorrectly routed wiring, pinch damage from previous service, or added electrical accessories can compromise the purge valve circuit and induce shorts.

5. PCM driver failure

An internal short in the PCM's output driver is possible but statistically uncommon; it should only be considered after the solenoid and entire harness are proven fault-free.

How it's diagnosed

  1. Visually inspect the purge valve, its connector, and nearby wiring for chafing, corrosion, or physical damage
  2. Disconnect the purge valve and measure its coil resistance, comparing the result to factory specification
  3. With both the valve and PCM disconnected, test the circuit wiring for shorts to ground, power, or between adjacent circuits
  4. Apply a fused power and ground source to the valve to verify it actuates and draws normal current
  5. If the valve and wiring test normal, investigate a PCM driver fault only as a last resort after exhaustive electrical validation

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationSAE generic — identical on every make

Frequently asked

Is it safe to drive with P0445?

Short trips are generally safe, but the EVAP system is not purging vapors correctly, which increases emissions and may cause a rough idle if the valve is stuck open.

Will P0445 cause my vehicle to fail an emissions test?

Yes, an active P0445 normally results in a failed emissions inspection because it confirms a malfunction in the evaporative emissions control system.

My mechanic says I need a new engine computer for P0445. Is that true?

Usually no. The purge valve or its wiring is the actual cause in the vast majority of cases. A PCM failure is rare and should only be considered after thorough testing rules out the solenoid and harness.

Can I just clear the code and see if it returns?

Clearing the code may turn off the light temporarily, but if the solenoid or wiring is genuinely shorted, the code will almost always return immediately or within a short drive cycle.