P24B1 code meaning
Particulate Matter Sensor Circuit High
Powertrain system Generic code P24xx codes Check engine light
What P24B1 means
P24B1 reports the electrode side of the particulate matter sensor reading high, which usually points to a short to a voltage source or to a soaked, conductive element. Ford's 2023 diesel summary sets it when electrode current exceeds 41 µA for about 3 s during measurement. GM's 18OBDG04 table looks for an electrode supply reading above 4.1 V in the sensor control unit (30 of 60 samples, Type B), and VW's 2014 Touareg list uses 0 V or more than 4.1 V. Mazda bulletin 01-005-22 for the 2018–2019 CX-5 SKYACTIV-D 2.2 blames condensate on the element and raised detection from one to two drive cycles. Ford 18-2225 replaces the sensor on 2017–2018 Super Duty 6.7L trucks. P24B0 is the low counterpart.
P24B1 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 repairAfter a drive cycle
Symptoms of P24B1
- Malfunction indicator lamp on
- Particulate filter monitor does not complete
Common causes of P24B1
- Most likelyCondensate on the sensor element making it conductive
- PossibleElectrode line shorted to a voltage source
- PossibleInternal sensor fault, replacement sensor needed
- Less likelyControl software needing an update
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Particulate matter sensor
What each part of P24B1 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). |
| B1 | The exact fault in that area. |
What to do next
- Note P24B1 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 P24B1
What does P24B1 mean?
P24B1 means "Particulate Matter Sensor Circuit High". P24B1 reports the electrode side of the particulate matter sensor reading high, which usually points to a short to a voltage source or to a soaked, conductive element. It is a generic code, so it means the same on every make.
Is it safe to drive with P24B1?
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 P24B1 fail an emissions test?
Yes, it can. P24B1 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 P24B1 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 P24B1 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.