What it means
The EVAP pressure sensor/switch C reports a circuit intermittent condition. Tank pressure plausibility for leak detection on this branch is impaired.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
EVAP pressure sensor/switch C supplies pressure information the control module uses to check the fuel-vapor system for leaks. This code sets when the C circuit signal comes and goes or becomes unreliable, disrupting pressure plausibility checks.
Common causes
Most likely first.
- Sensor connector not seated
- Noisy ground reference
- Connector with intermittent contact under vibration
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
How to diagnose it
- Save freeze-frame data and review live EVAP pressure readings for dropouts, spikes, or changes that coincide with the fault.
- Check that sensor C's connector is fully seated, then inspect its pins and harness for corrosion, looseness, chafing, or vibration-related damage.
- With live data or a meter connected as appropriate, gently move the harness and connector to see whether the signal becomes unstable.
- Check sensor ground and reference connections for voltage fluctuations or poor contact, comparing readings with the manufacturer's specification.
- If the wiring remains stable, test sensor C for intermittent output and inspect its mounting and connector fit.
Common fixes
- Reseat and secure sensor C's connector.
- Clean corroded terminals and repair loose or damaged connector pins.
- Repair chafed wiring or an intermittent ground/reference connection.
- Replace sensor C if its signal drops out despite stable wiring and connections.
Can I keep driving?
Normal driving is usually possible if the engine runs normally, but the intermittent fault can keep EVAP leak checks from completing and lead to an emissions inspection failure. A fuel smell near the tank or engine bay warrants prompt attention.
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.