Volvo All Engines (2017 Emissions) Fault Code: P042000 PID: EMS Catalyst System Efficiency Below Threshold

Volvo All Engines (2017 Emissions) Fault Code: P042000 PID: EMS Catalyst System Efficiency Below Threshold

This diagnostic function evaluates if the catalyst is converting the fuel from the aftertreatment hydrocarbon doser into enough heat at the beginning of the aftertreatment diesel particulate filter (DPF) regeneration. The aftertreatment DPF intake temperature sensor (post catalyst) should steadily increase and stabilize once the desired temperatures are met.

Conditions for diagnostic trouble code (DTC):
1) Catalyst outlet temperature reaction time too low to support hydrocarbon conversion

Observable symptoms
1) None

Probable cause
1) Obstructed/dirty aftertreatment hydrocarbon doser
2) Air purge system
3) Exhaust Gas Temperature (EGT) Sensor
4) Catalyst failure