P24D3 code meaning
Reductant Heater B Sense Circuit
Powertrain system Generic code P24xx codes Check engine light
What P24D3 means
P24D3 is the same kind of fault for heater B, which GM and Ford assign to the heated DEF line from pump to dosing valve. The read-back line of this heater is broken or delivers nonsense, so the controller cannot tell whether the hose is really powered; the narrower low and high cases are P248C and P248D. No manufacturer documents P24D3 in this sense. FCA uses the number differently: bulletin 18-008-23 for 2019 Jeep Compass diesels outside North America lists P24D3-00 as a particulate matter sensor supply voltage above threshold, fixed with new PCM software. GM's diesel tables from 2016 to 2018 describe a line heater sense check with a 3 V limit. A line that does not thaw blocks dosing in winter, so the fault deserves attention before frost.
P24D3 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P24D3
- Malfunction indicator lamp on
- DEF dosing faults or warnings at low temperatures
Common causes of P24D3
- Most likelyOpen sense wire or loose plug at the heated DEF line
- PossibleDamaged heated line with internal conductor fault
- Less likelyManufacturer-specific use of the code (FCA uses it for PM sensor supply), software update
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Reductant heater b
What each part of P24D3 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). |
| D3 | The exact fault in that area. |
What to do next
- Note P24D3 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 P24D3
What does P24D3 mean?
P24D3 means "Reductant Heater B Sense Circuit". P24D3 is the same kind of fault for heater B, which GM and Ford assign to the heated DEF line from pump to dosing valve. It is a generic code, so it means the same on every make.
Is it safe to drive with P24D3?
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 P24D3 fail an emissions test?
Yes, it can. P24D3 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 P24D3 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P24D3 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.