OBD-II trouble code
P0445: Evaporative Emission System Purge Control Valve Circuit Shorted
The EVAP purge valve's control circuit is shorted — excessive current or an always-energized valve, pointing at a shorted winding or grounded wire.
Quick facts
- System
- Powertrain
- Category
- EVAP System
- Severity
- Low severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $50 – $350
- DIY difficulty
- Intermediate DIY
What does P0445 mean?
P0445 is the short-circuit member of the purge-valve family: instead of no current (P0444), the computer sees too much. Either the purge solenoid's winding has shorted internally — heat-cycling gradually breaks down winding insulation until resistance drops well below spec — or the control wire is chafed to ground, holding the valve energized whenever the circuit is powered.
A shorted-to-ground control wire has a distinctive consequence: the purge valve can be held open continuously, purging the canister at times the computer never intended. That shows up as rough idle, stumble on startup, hard starts right after refueling, and sometimes lean trim codes. An internally shorted winding more often just trips the driver's overcurrent protection and sets the light.
Diagnosis is a multimeter job: winding resistance far below spec condemns the valve; normal resistance means unplugging it and checking the harness for shorts to ground and to voltage, paying attention to chafe points.
Common causes
- Internally shorted purge solenoid winding
- Control wire chafed/shorted to ground
- Wiring shorted to battery voltage
- Corrosion or moisture bridging connector terminals
- PCM driver damage from a sustained short (rare)
Symptoms
- Check engine light on
- Rough idle or stumble if the valve is being held open
- Hard starting after refueling (continuous purge)
- Possible lean codes or fuel-trim shifts
- Blown fuse in some configurations
Diagnostic steps
- 1.Measure the purge solenoid's winding resistance — well below spec (often reading just a few ohms) means an internal short; replace the valve.
- 2.If resistance is normal, disconnect the valve and test the control wire for shorts to ground and to voltage.
- 3.Inspect the harness for chafe points near brackets and hot components.
- 4.Check the connector for moisture or corrosion bridging pins.
- 5.After repair, command the valve with a scan tool and confirm normal on/off behavior and current draw.
- 6.Clear codes and verify fuel trims return to normal.
Repair cost
$50 – $350
Typically a $20-$100 purge valve with minimal labor. Harness chafe repairs are modest. If the short was long-standing, confirm the PCM driver survived — rare, but worth verifying before closing the job.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with evap system repair preselected. Adjust labor rate and vehicle category to fit your situation.
Related repairs
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.