2018 Freightliner Cascadia DD15 - Forced Regen Fails and SCR Efficiency Low Derate

Question

I am stuck in a 5 MPH derate on the side of I-80. Every time I try to run a parked regen, it gets about 10 minutes in and then just kicks out with a 'Regen Aborted' message on the dash. The MIL is on and I can't get any power to pull hills.

Megan Rivera · Accepted Answer

The issue was a completely failed Hydrocarbon (HC) Doser injector located in the exhaust elbow. It was clogged, so fuel wasn't reaching the DOC to create the heat needed for the regen. I replaced the HC Doser (part number EA0010101151, approx $320), performed a code reset using Detroit Diagnostic Link 8.15, and ran a successful service regen. Once temps hit 600C, the SCR code cleared and the derate was lifted.

dieselmike88 · Answer

Check your DEF doser valve nozzle (A0001405339). These carbon up or get crystallized DEF on the tip which prevents a good spray pattern, leading to those efficiency codes.

Tom Patel · Answer

You need to look at the SCR inlet and outlet temperature sensors. If the temperature delta isn't reaching at least 500 degrees during the start of the regen, the MCM will abort the process for safety.

Chris Donovan · Answer

Have you performed a low volume quantity test on the DEF pump? If the pump isn't maintaining 130 PSI, it won't atomize correctly and the SCR catalyst won't be able to reduce NOx levels properly.

2018 Freightliner Cascadia DD15 - Forced Regen Fails and SCR Efficiency Low Derate

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