Fault Family
System: Powertrain (P-Codes)
2 SAE Codes
DPF Ash Accumulation
Diagnostic & Technical Explanation
Code P242F (Particulate Filter Restriction - Ash Accumulation Bank 1) sets when the ECM's DPF loading model, corrected for total regeneration cycles and mileage, determines the filter's incombustible ash content from engine oil additives and metallic wear particles has built up enough to meaningfully restrict exhaust flow. Unlike soot, ash cannot be burned off by regeneration and only accumulates over the filter's service life, so once the model flags it the only durable fix is professional filter cleaning or replacement.
These 2 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 2 times.
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)