Volvo All Engines (2013 Emissions) Fault Code: P055A12 PID: EMS Engine Oil Pressure Sensor/Switch “B”

Volvo All Engines (2013 Emissions) Fault Code: P055A12 PID: EMS Engine Oil Pressure Sensor/Switch “B”

Circuit description
The Engine Piston Cooling Oil Pressure Sensor is used to detect engine piston lubrication and cooling system failures. The sensor consists of a pressure sensitive diaphragm and amplifier. Engine piston cooling oil pressure causes the sensor’s diaphragm to deflect and produce an electrical signal proportional to the pressure. The diaphragm deflection signal is amplified in the sensor.

The sensor’s signal is monitored by the Engine Control Module (ECM).

The engine control module (ECM) will set a diagnostic trouble code (DTC) and derate the engine to avoid engine damage if the sensor signal is not within predetermined limits, or the signal is not rational.

Conditions for diagnostic trouble code (DTC)
The voltage at pin A14.EB:19 is above normal value

Diagnostic operating conditions
Ignition key in ON position

Observable symptoms
The engine oil pressure (EOP) gauge shows 0 when the engine is running

Probable cause
1) Connector
2) Open circuit, Ground wire
3) Short circuit to 5V, Signal wire
4) Short circuit to battery voltage, Signal wire
5) Engine Piston Cooling Oil Pressure Sensor