Practice question

A school bus diesel passive/active diesel particulate filter (DPF) regeneration is not completing, and soot loading keeps rising. A likely cause is:

  1. Predominant low-load idling/short trips preventing adequate exhaust temperature for regeneration, or a regeneration-system fault
  2. Excessive long highway runs at high load
  3. A new fuel filter
  4. Fresh engine oil

Answer: A — Predominant low-load idling/short trips preventing adequate exhaust temperature for regeneration, or a regeneration-system fault

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Practice more: ASE S2 Diesel Engines (School Bus) Practice Questions - ASE S2 - Diesel Engines (School Bus) Certification Exam →