Powertrain, generic (extended)

P246C Particulate Filter Restriction - Forced Limited Power (Bank 1)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P246C is the final stage of the bank 1 filter loading monitor: the filter is judged so clogged that the controller reduces engine output to protect engine and filter. Ford uses it on diesels with an immediate MIL plus wrench light. In the 2015 summary a normalised restriction of twice the normal soot value above 625 rpm for 300 s sets it and EGR is switched off; the 2023 summary uses an estimated soot mass of 200 % of the normal regeneration trigger. Ford's 2024 petrol summary applies the code to the gasoline filter as well, with normalised back pressure above 1.0 for 5 s once the filter is above 250 °C at 400–850 m³/h. Ford bulletins for the 3.2 L Transit (18-2064) and 6.7 L Super Duty (21-2052) pair it with P2463 and fix it by forced regeneration or new PCM software. Bank 2 is P243B.

Likely causes

Soot overload after repeatedly missed or aborted regenerations
Mostly stationary or low-speed operation without full regenerations
Filter at the end of its life with high ash content
PCM calibration overestimating soot load (Ford bulletins)

Symptoms

  • MIL and service or wrench light on
  • Marked loss of power (limp mode)
  • Drive-to-clean or filter full message

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–3,000
Time0.5–4 h

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

Parts involved

dpf b1

Related codes

P2463P243BP2459P244BP246B

References: fordservicecontent.com, fordservicecontent.com, fordservicecontent.com, static.nhtsa.gov.