Kenworth T680 Paccar MX-13 Forced Regen Required - 5mph Derate in 15 Miles

Question

My 2018 T680 is stuck in a low-power state and DAVIE is showing a soot level high warning on the dash. I try to initiate a parked regen but the switch just flashes and nothing happens even with the parking brake set and neutral selected. I am worried about hitting the 5mph derate timer before I can get back to the yard.

Lina Brooks · Accepted Answer

The issue was a failed Differential Pressure Sensor (Part #2111289) and a clogged Dosier Valve. The sensor was reading 0 psi even under load, so the ECM didn't think it needed to finish the burn sequence. I replaced the sensor, cleaned the carbon off the DPF nozzle, and performed a 'DPF Service Regeneration' via the diagnostic port which cleared the 5mph derate. Total part cost was about $340 including the sensor and a new gasket for the doser.

wrenchqueen · Answer

Verify that your coolant temperature is at least 150 degrees Fahrenheit. The MX-13 won't even try to start a parked regen if the engine is too cold; you might need to high-idle it manually for a bit first.

Sam Holloway · Answer

You need to look at the 7th injector (hydrocarbon injector) and ensure the fuel line isn't clogged. If the exhaust temps don't rise quickly enough during the 'start-up' phase of the regen, the ECM will abort the process for safety.

hd_trucker_77 · Answer

Check your clutch switch or neutral safety switch status in the data stream. If the ECU doesn't see a confirmed neutral signal or thinks the clutch is depressed, it will refuse to command the high idle needed for the burn.

Kenworth T680 Paccar MX-13 Forced Regen Required - 5mph Derate in 15 Miles

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