P24FE code meaning
SCR Catalyst Incorrect
Powertrain system Generic code P24xx codes Check engine light
What P24FE means
P24FE means the controller concludes that the SCR catalyst is missing or not the expected part. Ford runs this test on the 6.7 L diesel (2023 summary) for about 60 s with SCR inlet at 195–340 °C and feedgas NOx of 70–500 ppm, and sets the code when cumulative SCR efficiency falls below 0 %. Hino's J08E workshop text (SB-19-008, 2017–2020 conventional trucks) treats it as removal of the DEF SCR catalyst: average NOx conversion at or under 0.03 for 10 s, MIL off but service lamp on, low power. Hino alert SA-17-036 had first told dealers to clear and release trucks. Ford TSB 24-2136 links P24FE on 2020–2022 Super Duty to NOx sensor 11, fixed by a new sensor and software. Ordinary ageing is P20EE.
P24FE at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P24FE
- Warning or service lamp (Hino sets the service lamp, MIL stays off)
- Reduced engine power
- NOx downstream of the SCR as high as upstream in live data
Common causes of P24FE
- Most likelyUpstream or downstream NOx sensor misreading (Ford sensor 11, Hino NOx sensors)
- PossibleSCR catalyst removed or replaced by a non-matching part
- PossibleController software detecting removal falsely, fixed by reprogramming
- Less likelyDiluted DEF or faulty DEF injector collapsing NOx conversion
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
SCR catalystNox sensor
What each part of P24FE 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). |
| FE | The exact fault in that area. |
What to do next
- Note P24FE 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 P24FE
What does P24FE mean?
P24FE means "SCR Catalyst Incorrect". P24FE means the controller concludes that the SCR catalyst is missing or not the expected part. It is a generic code, so it means the same on every make.
Is it safe to drive with P24FE?
Drive gently and only to a workshop. With P24FE the car can go into limp mode (reduced power) to protect itself.
Will P24FE fail an emissions test?
Yes, it can. P24FE 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 P24FE to fix?
Difficulty: hard. A typical repair takes 0.5 to 5 hours of work. This is a job for a workshop.
Will P24FE 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.