Diagnostic trouble code (DTC) information

Condition 

Fig 1: Identifying Fuel Tank Pressure Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fuel tank pressure usually changes when the canister purge (CP) valve is operating. Diagnostic trouble code (DTC) ECM-402A is stored in the engine control module (ECM) if the fuel tank pressure is constant when the canister purge (CP) valve is constant.

Substitute Value 

• The engine control module (ECM) assumes a fuel tank pressure of 0 hPa

Possible Source 

Faulty signal: 

• defective hoses
• defective manifold absolute pressure (MAP) sensor
• major leak.

Fault symptom[s] 

None.