P249CExcessive Time To Enter Closed Loop Reductant Injection Control
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P249C covers the SCR dosing strategy rather than a part: after start-up the engine controller is expected to switch from fixed, map-based urea dosing to dosing corrected by the NOx sensor signal, and this code means that switch happened too seldom or too late. Ford's 2023 diesel summary checks how much of the operating time was really spent in closed loop compared with what was expected, with SCR temperature between 160 and 550 °C, coolant above 70 °C and a 300 s run. Usual reasons are a NOx sensor not yet ready, implausible exhaust temperatures or a cold SCR. P249D and P249E report the opposite case, a loop that runs but has run out of correction range. The driver usually only sees the warning lamp.
- What you may notice
- Malfunction indicator lamp on
- Often no noticeable change in driving behaviour
- NOx sensor or exhaust temperature codes may be stored as well
- Likely causes
- LikelyDownstream NOx sensor slow to become ready or faulty, so closed loop cannot start
- PossibleImplausible exhaust gas temperature signal upstream or downstream of the SCR
- PossibleMostly short or cold trips keep the SCR below its working temperature
- RareEngine control software calibration requiring an update
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.