2018 Freightliner Cascadia DD15 - Forced Regen Fails and Derate Active

Question

I am stuck at a rest area in Nebraska with a dash warning saying 'Service Regen Required' and the truck is now in a 5 MPH derate. Every time I try to start a parked regen, it runs for about 10 minutes and then just cancels itself without any specific error message on the dash.

Sam Holloway · Accepted Answer

The issue ended up being a failed Hydrocarbon Doser Valve (part number A0004900500). The nozzle was completely blocked with carbon soot. I removed the doser, cleaned the port with a wire brush, and installed a new valve which cost about $350. After clearing the codes with the laptop and performing a Service Routine 'DPF Ash Accumulator Reset', the forced regen completed successfully in 45 minutes and the derate was lifted.

torque_terry · Answer

Inspect the intake throttle valve. Sometimes they get stuck partially closed or open, which messes up the air-to-fuel ratio required to hit the thermal management targets for a successful burn.

shoptech_carlos · Answer

Check your DOC inlet temperatures using DiagnosticLink if you have it. If the temps aren't getting above 500 degrees during the warmup phase, the MCM will abort the regen for safety.

Ashley Park · Answer

You might have a clogged hydrocarbon (HC) doser injector. If the seventh injector is carboned up, it can't spray the fuel needed to cook the DPF, causing the software to timeout.

2018 Freightliner Cascadia DD15 - Forced Regen Fails and Derate Active

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