Volvo All Engines (2017 Emissions) Fault Code: P047511 PID: EMS Exhaust Pressure Control Valve “A”

Circuit description
The purpose of the engine exhaust brake closed loop butterfly valve (butterfly valve) is to create a controlled exhaust back pressure upstream of the butterfly valve. The butterfly valve consists of the housing, shutter, shaft, bushings, pneumatic actuator, spring, and a bracket assembly. The shutter is kept in an open position by the spring when not activated. A pneumatic actuator closes the shutter when activated. The actuator is activated by the Engine Control Module (ECM). An exhaust pressure sensor located upstream from the shutter monitors the upstream exhaust pressure. The ECM activates the pneumatic actuator and closes the shutter when the upstream exhaust pressure deviates from the requested value. Once the pneumatic actuator is deactivated, the shutter returns to the open position

Conditions for diagnostic trouble code (DTC)
Short circuit to ground on A14.EB:38

Diagnostic operating conditions
Ignition key in ON position

Observable symptoms
Exhaust pressure governor constantly activated
The engine brake does not function
Low Power
Black smoke

Probable cause
1) Control wire
2) Short circuit in control valve