P24D6EVAP System Pressure Sensor/Switch B Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P24D6 is a plausibility fault of EVAP pressure sensor B. GM's 2023 table 23OBDG03A checks the canister vapour pressure sensor at the start of a cold drive: after more than 3,600 s soak the offset must sit within a window around barometric pressure; a filtered ratio above 0.73 sets the code, Type A. GM bulletins 24-NA-162 and 24-NA-258 trace P24D6 on 2024–2025 Silverado and Sierra HD 6.6L trucks to a narrow-range sensor fitted at the plant (about 1.5 V instead of 2.625 V at rest). Mitsubishi's 2023 Outlander PHEV compares tank, differential and canister pressures for 180 s during the engine-off test. Audi lists it for V6/V8 sensor G950, FCA for 2017–2018 Giulia software. P24D7/P24D8 are hard voltage limits.
- What you may notice
- Malfunction indicator lamp on
- Other EVAP codes such as a switching valve fault may appear alongside
- No driveability change
- Likely causes
- LikelyWrong sensor version installed (GM HD trucks, narrow-range instead of wide-range)
- PossibleSensor offset drifted away from barometric pressure
- PossibleKinked hose or blocked port at the sensor
- RareEngine control software needing an update (FCA, Audi)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.