P24D8 code meaning
EVAP System Pressure Sensor/Switch B Circuit High
Powertrain system Generic code P24xx codes Check engine light
What P24D8 means
P24D8 reports EVAP pressure sensor B reading above its valid voltage. In GM's 2023 table 23OBDG03A the canister pressure sensor fails above 4.85 V, 97 % of the reference, counted over 640 of 800 samples and treated as Type B. Mitsubishi's 2023 Outlander PHEV applies 4.1 V for 2 s to its absolute tank pressure sensor, which shows about 101 kPa at sea level when healthy. Audi's bulletin 2069531 lists P24D8 as pressure sensor 2 shorted to positive and also shows it among codes logged under a wrong label, to be tested as sensor G950. Common findings are an open sensor ground, a signal wire touching the 5 V or 12 V supply, or an internal failure. Compare P24D7 for the low side.
P24D8 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 1.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P24D8
- Malfunction indicator lamp on
- EVAP readiness monitor incomplete
Common causes of P24D8
- Most likelyOpen ground of sensor B, signal floats high
- PossibleSignal wire shorted to reference or battery voltage
- PossibleEVAP pressure sensor B failed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
EVAP pressure sensor b
What each part of P24D8 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| D8 | The exact fault in that area. |
What to do next
- Note P24D8 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P24D8
What does P24D8 mean?
P24D8 means "EVAP System Pressure Sensor/Switch B Circuit High". P24D8 reports EVAP pressure sensor B reading above its valid voltage. It is a generic code, so it means the same on every make.
Is it safe to drive with P24D8?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P24D8 fail an emissions test?
Yes, it can. P24D8 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P24D8 to fix?
Difficulty: medium. A typical repair takes 0.5 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P24D8 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.