Powertrain, generic (extended)

P249C Excessive Time To Enter Closed Loop Reductant Injection Control

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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.

Likely causes

Downstream NOx sensor slow to become ready or faulty, so closed loop cannot start
Implausible exhaust gas temperature signal upstream or downstream of the SCR
Mostly short or cold trips keep the SCR below its working temperature
Engine control software calibration requiring an update

Symptoms

  • Malfunction indicator lamp on
  • Often no noticeable change in driving behaviour
  • NOx sensor or exhaust temperature codes may be stored as well

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–700
Time1–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

scr catalystreductant injection control

Related codes

P249DP249EP20EEP202E

References: fordservicecontent.com, law.cornell.edu.