Powertrain, generic (extended)

P2DCD Particulate Filter B Incorrect

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

P2DCD is meant for a second particulate filter, labelled B, that the engine control unit finds to be absent or not the specified part, for instance after the filter has been cut out, replaced by an empty housing or swapped for an unsuitable aftermarket unit. No manufacturer documents P2DCD publicly, and makers catch such tampering with other codes. CARB's rules for diesel vehicles and heavy-duty engines require a fault when the filter body is wrecked or taken out, or the whole unit gives way to a silencer or plain tube. Ford's 2024 gasoline summary performs this check on its second filter as P226E (bank 2): with exhaust flow of 300 to 850 m³/h and the filter above 250 °C for 30 s, normalised backpressure under 1.0 for 5 s means a missing brick. Filter A: P24FD. Expect a MIL and a failed inspection.

Likely causes

Filter B removed or replaced by an empty housing or pipe

Unsuitable replacement filter fitted

Filter substrate cracked, melted or blown out

Leaking or blocked pressure lines misleading the detection

Symptoms

Check engine light on
Failed emissions inspection
Louder exhaust or visible soot at the tailpipe

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€100–3,000

Time1–4 h

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

Parts involved

particulate filter b

Related codes

P24FD P226E P226D P2003 P243B

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