What it means
The control module detects a high signal in the EVAP system switching valve control circuit. This is an electrical fault, not a valve-stuck-closed code.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The EVAP system uses a switching valve to route fuel vapour during emissions testing and purge operation. This code sets when the module detects a high electrical signal in that valve's control circuit, pointing to a circuit or connection problem rather than proving that the valve is mechanically stuck.
Common causes
Most likely first.
- Control circuit shorted to voltage
- Open or high-resistance circuit
- Faulty valve or poor connector contact
Symptoms
- Check engine light on
How to diagnose it
- Read freeze-frame data and other EVAP codes to identify when the high circuit signal was detected and whether the fault is isolated to the switching valve.
- Inspect the EVAP switching valve connector and harness for disconnected plugs, corrosion, chafing, or damage that could let the control wire contact voltage.
- Check the valve and connector for poor terminal contact or evidence of moisture, contamination, or heat damage.
- With the vehicle wiring diagram, measure the switching-valve control circuit for an unintended voltage or an open/high-resistance connection.
- Test the valve and module-side control circuit against the manufacturer's specifications to distinguish a valve fault from a wiring or driver fault.
Common fixes
- Reconnect or clean a poor EVAP switching-valve connector contact.
- Repair a control wire shorted to voltage or an open/high-resistance section of the circuit.
- Replace the EVAP switching valve if testing confirms an internal electrical fault.
- Repair a confirmed module-side control fault.
Can I keep driving?
The vehicle is generally driveable if it runs normally, but the EVAP fault can prevent emissions checks from passing and may increase vapour emissions. Arrange diagnosis soon, especially if other fuel-system symptoms appear.
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.