PACCAR MX-13 Fault Code 1995 - DPF Regen Incomplete

Question

My 2018 Peterbilt 579 is throwing code 1995 and aborting every parked regeneration after about 10 minutes. The dash displays a notification that the soot level is critically high but the exhaust gas temperature doesn't seem to climb high enough to burn it off during the cycle. I am worried about the truck going into Derate 5 MPH if I can't get this cleared today.

garagegrease · Accepted Answer

The issue was a failed Hydrocarbon Dosing Module (7th injector) unit itself. While the tip looked clean, the internal solenoid was sticking when it got hot, causing the fuel flow to drop off mid-cycle. I replaced the Hydrocarbon Doser (Part #2102148PE) and the fuel line gaskets. After installing the new unit and clearing the codes with DAVIE, the truck completed a full 45-minute parked regen and the soot level dropped from 110% to 5%. Cost for the part was roughly $650.

Greg Walters · Answer

You need to perform a fuel pressure test on the aftertreatment fuel manifold. Even if the injector is clean, the Hydrocarbon Dosing Valve might be failing internally and not maintaining the 4.5 to 5.0 bar pressure required for a clean spray pattern.

Rachel Nguyen · Answer

I had this same issue on a Kenworth last month. Turned out to be the Turbocharger Actuator not closing enough to create the backpressure needed to drive up the initial exhaust temps. Check your VGT calibration.

Chris Donovan · Answer

Check your DOC inlet temperatures using DAVIE software. If the face of the DOC is plugged with face-ash or oil, it won't allow the oxidation process to generate the heat needed for the DPF soak.

PACCAR MX-13 Fault Code 1995 - DPF Regen Incomplete

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