P009B Code: Meaning, Causes, and Symptoms | OBD2 Codes

P009B – Fuel Pressure Relief Control Circuit/Open


P009B Possible Symptoms


Engine Light ON (or Service Engine Soon Warning Light)


P009B Possible Causes


Faulty Fuel Pressure Relief Valve,Fuel Pressure Relief Valve harness is open or shorted,Fuel Pressure Relief Valve circuit poor electrical connection


P009B Description


The Engine Control Module (ECM) uses the Fuel Rail Pressure (FRP) sensor to monitor the high side fuel pressure and the fuel rail pressure relief valve performance. The fuel rail pressure relief valve is designed to release fuel pressure in the event of an overpressure condition. This diagnostic looks for excessive fuel rail pressure decay to detect an open fuel rail pressure relief valve.