DPF HC Absorption Codes


During extended periods at idle speed or high idle, unburned fuel from the combustion
process slowly builds up in the Aftertreatment Device/One Box. This unburned fuel is also referred
to as hydrocarbon.
If too much hydrocarbon is allowed to accumulate in the ATD, the next drive cycle could result in
higher than normal internal ATD temperatures as the hydrocarbon burns off. This could
potentially cause a failure of the Diesel Particulate Filter (DPF).
The Auto-Elevate feature eliminates the hydrocarbon buildup from reaching critical levels by
automatically increasing engine RPM. This process results in a temporary increase of exhaust
temperatures that effectively burn off the hydrocarbons within the ATD.

if Auto-Elevate is NOT enabled, excessive idle time may result in:

  • 1037/15 DPF HC Absorption Warning
  • 1037/0 DPF HC Absorption Very High
  • 1037/16 DPF HC Absorption High
  • 3250/14 Abnormal DOC Temperature Rise 2


The parameter to enable/disable this feature is located in the ACM group
“PGR005_DPF,” and is called “Extended Idle Auto RPM Elevate.”

It is a programmable feature via DDDL. It is defaulted to “OFF”. With Auto-Elevate enabled and after a predetermined amount of idle time, the DDEC 10 ACM
(Aftertreatment Control Module) will automatically elevate engine speed to 1100 RPM for up to
20 minutes. This will raise exhaust temperatures and eliminate hydrocarbon buildup in the ATD. When the process is complete, the engine returns to idle speed and the timer for Auto-Elevate resets.



Detroit Diesel does NOT recommend activation of the Auto-Elevate feature for PTO driven units. The automatic engine speed ramp-up could result in unexpected PTO operation. This is a potentially dangerous situation which may create chance of injury/death.



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