Fault Family
System: Powertrain (P-Codes)
2 SAE Codes
DPF Forced Limited Power
Diagnostic & Technical Explanation
Code P243B (Particulate Filter Restriction - Forced Limited Power Bank 2) sets when the ECM detects the DPF is restricted enough that it derates engine power to protect the filter and turbo from an uncontrolled thermal event during an eventual regeneration, a more advanced stage than a standard soot-accumulation warning. Causes are a long stretch of driving with no completed regeneration, a stuck-closed EGR cooler bypass adding extra soot, or a failed differential pressure sensor preventing the ECM from ever commanding regeneration.
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)