P24B8EVAP System Leak Detection Pump Pressure Sensor Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P24B8 is the general circuit fault of the pressure sensor that sits inside an evaporative leak check module together with the pump and the switching valve. The sensor gets a 5 V reference from the engine computer and reports canister-side pressure during the engine-off leak test. No manufacturer documents P24B8 publicly; GM, Mitsubishi and Subaru use the more specific P24B9 to P24BB for this sensor. CARB requires such EVAP input components to be checked for circuit faults and implausible values. With this fault present, the leak test cannot be trusted and will not complete, so the EVAP readiness flag stays open. Typical findings are a broken reference or ground wire, a corroded module plug or a failed module.
- What you may notice
- Malfunction indicator lamp on
- EVAP readiness monitor does not complete
- Likely causes
- LikelyOpen or shorted 5 V reference, ground or signal wire to the leak check module
- PossibleCorroded or loose connector at the leak check module near the canister
- PossiblePressure sensor inside the leak check module failed
- RareEngine control module does not supply the sensor reference
- 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: €50 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.