P0193 is a common OBD-II code. It indicates that a vehicle’s fuel rail pressure sensor is sending a signal to the PCM that is above its normal operating range (in terms of voltage value).
While P0193 is a generic code (it has the same meaning for any vehicle made for the 1996 model year and up), it is almost always seen in Ford vehicles.
With P0193 there can only be two things going on:
- The fuel pressure reading is correct and abnormally high (likely a fuel pressure regulation issue).
- The fuel pressure reading is incorrect (bad fuel pressure sensor, or wiring issue).
P0193 Symptoms
Drivability is usually affected, even if it’s just a bad sensor.
Stalling
With too much fuel getting to the fuel injectors or the PCM, the engine may stall out or hesitate in certain situations. There may also be a noticeable lack of power.
Air/Fuel Mixture Issues
Without a reliable reading from the fuel pressure sensor, your vehicle may end up with the wrong air/fuel mixture. If it runs too rich, you may get black smoke and P0172. If it runs too lean, you’re likely to have p0171 accompany P0193.
Unreliable Idle
P0193 can be caused when the fuel pressure regulator is bad. If the fuel pressure at the injectors is inconsistent, it’ll be really hard for your car or truck to maintain a steady idle speed. This can lead to the engine dying when coming to a stop as well.
Poor Fuel Mileage
Fuel mileage can suffer when the air/fuel mixture isn’t correct. You may also notice the stench of gas.
P0193 Causes
Here are the most common issues that cause P0193 to be thrown:
Fuel Pressure Sensor
The fuel pressure sensor is responsible for telling your vehicle’s ECM/PCM what the actual fuel pressure is. If it goes bad (or if the fuel pressure really is out of the normal range) P0193 can and will appear.
A bad fuel pressure sensor can force the vehicle to overwork the fuel pump, thinking that it’s constantly starving for fuel when it is not.
Wiring
Wiring issues can cause P0193 to be thrown. Take a look at the wiring harness around the fuel pressure sensor. Does it look broken or damaged? Is the connection to the sensor solid? If it looks bad, it may need to be replaced.
Fuel Pressure Regulator
The fuel pressure regulator is responsible for making sure that the amount of fuel pressure that reaches the fuel rail is at a constant level (which will be less than pushed by the fuel pump). If it goes bad, it can restrict the flow of fuel to the point that P0193 can be thrown.
P0193 Diagnosis
A good scanner can help you look at the conditions that were present when the code was set. You can also use it to check the fuel pressure reading as you drive. You’ll need to manually check the fuel pressure if the reading seems off.
If the manual fuel pressure reading is normal, then you know that you’ve got an issue with the fuel pressure sensor (or the wiring going to and from it).
If the fuel pressure reading is high, then it’s likely the fuel pressure regulator that’s causing P0193.
Conclusion
P0193 can be a difficult code to track down, but should not be ignored. Doing so very well could leave your vehicle stranded. If there is anything that you would like to add, please leave a comment below. Good luck.