P0190 - P0194 Fuel Rail Pressure

To continue the topic of the error codes, it is time to mention faults with Fuel Rail Pressure system. A fuel rail is essentially a pipe (usually resembling a rail) used to deliver fuel to individual fuel injectors on internal combustion engines.

• P0190 Fuel Rail Pressure 
• P0191 FRP Range/Performance
• P0192 FRP Low Input (voltage)
• P0193 FRP High Input (voltage)
• P0194 FRP Intermittent

Faults in the fuel rail are expressed with the codes P0190-P0194 and apply to all car manufacturers, it is standard. If after the diagnosis you see one of those codes, it means that you have an electrical or mechanical failure. The principle of this group of faults is based on how the incoming signal from the fuel rail pressure (FRP) sensor falling below a calibrated limit for a calibrated amount of time. The nature of the error is greatly influenced by the type of used fuel, the type of fuel system construction and the manufacturer who produced the car

The fuel supply unit is the most important structural mechanism that performs important functions and ensures the operation of the whole car. This system is formed by several structural parts, the joint operation of which ensures the execution of the working cycle of the whole complex. The appearance of any breakdowns in such a mechanism may result in the inability to use the entire vehicle directly for its intended purpose.

Symptoms of trouble codes P0190- P0194: 1) illuminated the MIL; 2) Lack of the engine power; 3) Problems with starting the engine.

Causes of  trouble code P0191

1. Interruptions in the VREF circuit (Voltage Reference);
2. Damage and failures in the operation of the FRP sensor;
3. Excessive resistance in the VREF circuit.

Causes of  trouble code P0192:

1. Fuel Pressure is low or high;
2. Damages of the sensor FRP;
3. Excessive VREF resistance;
4. Vacuum’s damages and other leaks in the system;
5. Low fuel level.

P0193 trouble code:

1. Short sensor signal for SIG RTN (signal return) or PWR GND;
2. Damaged sensor

Causes of trouble code P0194: 1) High fuel pressure and other causes similar to code P0192.

These trouble codes can be cleared with the inCarDoc app. If the errors come back again, then most likely the problem has mechanical nature and you need to check the sensor and other components for damage.