P249E code meaning
Closed Loop Reductant Injection Control At Limit - Flow Too High
Powertrain system Generic code P24xx codes Check engine light
What P249E means
P249E is the counterpart to P249D: here the SCR feedback has trimmed the dosing down to the lowest correction it is allowed, because more reductant seems to arrive than the NOx reading calls for. GM's 2014 diesel table flags a long-term adaptation factor below 0.41 (Type B); the 2018 table lists the low-side check as a two-trip Type B fault. Ford's 2023 summary uses the same 30 s clip rule as for P249D. A dosing valve that leaks or sticks partly open, overly concentrated fluid, ammonia slip being read by the NOx sensor as NOx, or a sensor that reads too low can all lead here. Ammonia smell at the tailpipe and white deposits around the injector are possible clues; drivability itself is rarely affected.
P249E at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor1 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P249E
- Malfunction indicator lamp on
- Ammonia smell from the exhaust
- White crystalline deposits at the dosing point
Common causes of P249E
- Most likelyDosing valve leaking or sticking partly open
- PossibleAmmonia slip from an aged or overloaded SCR catalyst seen by the NOx sensor
- PossibleNOx sensor reading too low
- Less likelyFluid concentration outside specification
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Reductant injector
What each part of P249E 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). |
| 9E | The exact fault in that area. |
What to do next
- Note P249E 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 P249E
What does P249E mean?
P249E means "Closed Loop Reductant Injection Control At Limit - Flow Too High". P249E is the counterpart to P249D: here the SCR feedback has trimmed the dosing down to the lowest correction it is allowed, because more reductant seems to arrive than the NOx reading calls for. It is a generic code, so it means the same on every make.
Is it safe to drive with P249E?
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 P249E fail an emissions test?
Yes, it can. P249E 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 P249E to fix?
Difficulty: medium. A typical repair takes 1 to 3 hours of work. This is a job for a workshop.
Will P249E 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.