P24D1 code meaning
Particulate Matter Sensor Regeneration Incomplete
Powertrain system Generic code P24xx codes Check engine light
What P24D1 means
Before each measurement the particulate matter sensor heats its element to burn off collected soot. P24D1 means that this cleaning phase did not finish properly. Ford's 2023 diesel summary flags the code when the sensor cannot return to measuring after regeneration, judged over 120 s. GM's 18OBDG04 table fails it when the electrode stays at or below 775 °C for 43 s during steady regeneration (25OBDG04A: 715 °C), Type B, and calls it heater degradation. Ford special service message 49846 replaces the sensor on 2017–2019 Super Duty and F-650/750 6.7L trucks, and FCA lists P24D1 for 2019 Jeep Compass diesels in bulletin 18-008-23 (PCM update). P24B7 points to a heater resistance fault, P24AF to an implausible electrode during cleaning.
P24D1 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 P24D1
- Malfunction indicator lamp on
- Particulate filter monitor does not complete
Common causes of P24D1
- Most likelySensor heater degraded, not reaching cleaning temperature
- PossibleHeavy deposits on the sensor element
- 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 P24D1 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). |
| D1 | The exact fault in that area. |
What to do next
- Note P24D1 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 P24D1
What does P24D1 mean?
P24D1 means "Particulate Matter Sensor Regeneration Incomplete". Before each measurement the particulate matter sensor heats its element to burn off collected soot. It is a generic code, so it means the same on every make.
Is it safe to drive with P24D1?
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 P24D1 fail an emissions test?
Yes, it can. P24D1 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 P24D1 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 P24D1 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.