IMPORTANT: Replace DPF and perform the Ash Accumulator reset using the diagnostic service tool.

NOTE: The DPF lamp will illuminate and code 3720/15 will log when the truck reaches the appropriate mileage interval. This fault indicates that the DPF needs to be replaced and the DPF Ash Accumulator routine in the diagnostic service tool must be completed. This routine can be found in the actions drop-down menu and must be completed after the DPF has been replaced.

NOTE: Using alternate cleaning methods may result in the cleaned DPF failing to reach the next ash clean interval. There may be damage to the Diesel Oxidation Catalyst (DOC) or DPF assemblies as a result of alternate cleaning methods.

NOTE: This code indicates the DPF has reached the end of its service life and must be replaced. Replace the DPF or attempt to have it cleaned.