Volvo All Engines (2017 Emissions) Fault Code: P040398 PID: EMS EGR “A” Control

Volvo All Engines (2017 Emissions) Fault Code: P040398 PID: EMS EGR “A” Control

Circuit description
The EGR Valve operation is controlled by the Engine Control Module (ECM) using a pulse width modulated signal.  The ECU provides both the power and ground circuits. The EGR Valve assembly consists of a solenoid, operating a valve by hydraulic pressure provided by the engine’s oiling system.

Conditions for diagnostic trouble code (DTC)
Too high temperature

Observable symptoms
Loss of power

Probable cause
1) EGR Valve