Component Location
General Description
Fuel Pressure Regulator Valve(FPRV) is integrated with high pressure pump and controls common rail pressure as regulating the quantity of fuel which is delivered to common rail. In order to control rail pressure to be optimum to current driving condition, ECM controls fuel pressure regulator valve operating current(with the method of duty-control) using RPCV signal, RPM and APS signal.
The lower Fuel pressure regulator valve current is, the more fuel is supplied to common rail. Thus it leads rail pressure to be high. On the contrary, the higher Fuel pressure regulator valve current is, the less fuel is supplied to common rail. Thus it leads rail pressure to be low. Therefore, when Fuel metering unit current becomes "0", as if there is open spot in FPRV circuit or connector is disconnected, maximum fuel quantity is supplied to common rail, so the pressure of common rail rise to maximum value.
DTC Description
P0253 is set when power is not supplied to ECM connector(C06-2) terminal 4 due to open or short to ground in fuel pressure regulator control circuit.
DTC Detecting Condition
Item | Detecting Condition | Possible Cause |
Threshold Value | ? Open or short to ground in FPRV control circuit (OC/SC-) | ? FPRV circuit ? FPRV component |
Fail Safe | ? Idle RPM rises to 1000RPM. ? Pilot and post injection inhibited (engine noise occurs) ? Fuel return from injector inhibited ? Engine speed is limited under 3000RPM and engine power generaton drops to 50% ? Knock sensor signal is ignored(MDP learning inhibited) ? If failure is detected, engine shuts down after time delay. | Check lamp |
YES |
? OC (Open Circuit) : Open, SC- (Short Circuit - ) : Short to ground , SC+ (Short Circuit +) : Short to battery
Specification
FPRV resistance | Operating frequency |
4?~5? (20?) | 400 Hz |
Schematic Diagram
Signal Waveform