J1939 SPN 2929 — Aftertreatment/Emissions parameter

What it means

Aftertreatment 1 Particulate Trap Soot Load Percent 2. This code indicates that the engine control module (ECM) has detected that the soot load in the Diesel Particulate Filter (DPF) has reached a high level (typically Level 2 or 3) or that there is a rationality fault with the soot calculation.