Fault Family System: Powertrain (P-Codes) 4 SAE Codes

DPF Efficiency Performance

Diagnostic & Technical Explanation

P2002 (Particulate Filter Efficiency Below Threshold Bank 1) sets when the differential-pressure or soot-model calculation shows the diesel particulate filter is passing more particulate matter than its efficiency threshold allows, or when an abnormal pressure-drop signature indicates a cracked or missing filter substrate. A substrate cracked or melted by an uncontrolled regeneration event, a swapped-in filter that lacks the correct catalytic coating, and a leaking or misrouted differential-pressure sensor hose are the most common causes.

These 4 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 4 times.

Codes in this family (4)

Code	Definition	Repair coverage
P2002	Particulate Filter Efficiency Below Threshold Bank 1	4 ranked fixes
P2003	Particulate Filter Efficiency Below Threshold Bank 2	4 ranked fixes
P226D	Particulate Filter Deteriorated/Missing Substrate Bank 1	4 ranked fixes
P226E	Particulate Filter Deteriorated/Missing Substrate Bank 2	4 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here:

Procedures 2..n after the first-listed procedure
Aftermarket parts cost ranges in USD (est_parts_cost_min/max_usd)
Professional labor-hour estimates (est_labor_hours)
Step-by-step diagnostic and repair instructions
Replacement-part mappings and catalog lookups
6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)

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