What it means
Same as P24D5 with the signal voltage above the plausible range. The evaporative system captures fuel vapor from the tank and purges it into intake; leaks or stuck purge valves leak hydrocarbons and cause emissions failures.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
EVAP pressure sensor or switch B monitors pressure in a secondary part of the fuel-vapor control system. This code sets when the B-circuit signal rises above the module's plausible range, which can happen if the signal wire contacts a supply voltage or the sensor circuit is faulty.
Common causes
Most likely first.
- Signal shorted to supply
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
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
- Review freeze-frame data and live sensor B voltage to confirm the signal is above range.
- Inspect the B sensor connector and harness for corrosion, loose pins, pinched insulation, or contact with a power feed.
- Check the sensor B signal wire for a short to supply voltage using the vehicle wiring diagram.
- Measure the signal at the sensor and module sides of the circuit to locate where the high voltage enters.
- If the circuit is sound, test pressure sensor or switch B against the manufacturer's specification.
Common fixes
- Repair a pinched or chafed B-circuit wire contacting a supply source.
- Clean and secure the sensor B connector or repair damaged terminals.
- Correct a short to supply voltage in the B signal circuit.
- Replace pressure sensor or switch B if its output remains high with correct circuit wiring.
Can I keep driving?
The vehicle is generally driveable, but the EVAP system may not monitor fuel-vapor pressure correctly and emissions inspection can fail. Stop if you detect a strong fuel smell or a visible leak.
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.