Powertrain, generic (extended)

P226D Particulate Filter Deteriorated/Missing Substrate (Bank 1)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P226D means the bank 1 particulate filter offers so little flow resistance that its core is likely broken, burnt out or removed. CARB requires detection of a destroyed or missing substrate, or a filter replaced by a pipe. GM's diesel tables test the filtered resistance of the DPF during soot loading above 500 rpm and 10 l/s exhaust flow: 5 failures in 10 samples (2018) or 20 in 30 below 0.01 kPa per l/s (2025), Type A. GM adds that a loose or blocked pressure-sensor pipe gives the same result; PIP5664 and an ECM update dealt with false P226D on 2020 6.6L L5P trucks, as did Mack and Volvo for 2015-16 MP engines. Ford also uses P226D for petrol particulate filters (2024-25: normalised back pressure below 1.0 for 5 s); 2025 Maverick and Bronco Sport 2.0L had the wrong pressure sensor fitted.

Likely causes

Filter core cracked, melted after an overheated regeneration, or removed
Differential pressure line disconnected, cracked, blocked or routed wrongly
Control software that sets the code without a hardware fault
Incorrect or faulty differential pressure sensor assembly

Symptoms

  • MIL on
  • Visible soot at the tailpipe if the filter core is damaged
  • Often no driveability change; regeneration behaviour may be affected

Repair estimate

DifficultyHardWorkshop job
Parts and labour€50–4,000
Time0.5–5 h

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

Parts involved

diesel particulate filterdpf differential pressure sensor

Related codes

P226EP2002P2463P2453P244A

References: law.cornell.edu, gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov.