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P05EB

Cold Start SCR NOx Catalyst Inlet Temperature Too Low

Same as P22FF but specifically during the cold-start window - the SCR catalyst inlet temperature does not reach the threshold needed for NOx reduction in the cold-start phase, so reductant injection cannot be enabled.

  • Check engine light: Yes
  • Emissions related: Yes
  • Repair difficulty: medium

Symptoms

  • Check engine light on
  • Failed emissions inspection
  • Possibly slightly increased fuel consumption
  • Sulfur (rotten egg) smell from exhaust under load

Common causes

Ordered by how often each turns out to be the cause.

  • Heat-up strategy not bringing exhaust to tempCommon

Parts involved

  • SCR Inlet Temperature Sensor
  • SCR Catalyst
  • Exhaust Heat Management

P05EB is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.