Paccar MX-13 Repeated Regen Failures and 5 MPH Derate

Question

My 2016 Kenworth keeps throwing a 5 mph derate after about 20 minutes of driving. I try to force a parked regen and it starts fine, but it keeps kicking out after 10 minutes saying 'Regen Aborted - System Not At Temperature'.

Mike Reynolds · Accepted Answer

The issue was a failed Hydrocarbon Doser Valve (A70-1002). The internal solenoid had an open circuit even though the tip looked clean. Replaced the doser valve assembly, performed a forced regen which finally reached the 1Low/High temp targets, and the derate cleared automatically. Total cost was about $450 for the part and 2 hours of labor including the software reset.

Dave Kowalski · Answer

Try performing a 'Doser Air Purge' test with Davie4 software. Listen for the solenoid click; if you don't hear it or if the pressure doesn't drop, the atomization unit might be dead.

Marcus Bell · Answer

Check your fuel pressure at the DAVCO filter first. If the lift pump isn't providing enough pressure to the hydrocarbon doser valve, the DOC will never get hot enough to light off the DPF.

Jordan Lee · Answer

You need to look at the 'DOC Intake Temperature' and 'DPF Intake Temperature' live data during the regen start. If the DOC temp doesn't climb rapidly, your 7th injector isn't spraying or the fuel line to it is clogged.

Paccar MX-13 Repeated Regen Failures and 5 MPH Derate

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