The P0193 trouble code gets stored in the trouble code memory when the engine control unit recognizes a too high signal from the fuel rail pressure sensor.
There could be some different causes of this, and in this article, you will learn what you need to know about the P0193 trouble code.
Code P0193 Definition
Fuel Rail Pressure Sensor – Circuit High Input
What does the P0193 code mean?
The P0193 code indicates that the engine control unit gets a too high signal from the fuel rail pressure sensor. It means that the signal is above the pre-calibrated limit for a pre-calibrated time made by the manufacturers.
Technically, it can mean that either the fuel pressure is too high or there is a problem with the signal from the fuel rail pressure sensor.
P0193 Trouble Code Symptoms
In most cases, when you experience the P0193 code, you will most likely only see the check engine light on your dashboard. It can also happen that the engine is running too rich, and this will cause the car to have performance issues and black smoke from the exhaust pipe.
The symptoms of code P0193 include:
- Check Engine Light
- Lack of power
- Hard starting condition
- Black smoke from the exhaust
- Performance Issues
Causes of the P0193 Code
In most cases, the P0193 code will be caused by a faulty fuel rail pressure sensor or a broken wire. However, in some cases, the fuel rail pressure can actually be too high caused by a faulty fuel pressure regulator or the vacuum hoses to it. The P0193 code may cause any of the following issues:
- Faulty Fuel Rail Pressure Sensor
- Faulty Fuel pressure sensor wirings
- Faulty Fuel pressure sensor connectors
- Faulty fuel pressure regulator
- Leaking vacuum hoses to fuel pressure regulator
- Faulty ECU
How serious is the P0193 Code?
Medium – The P0193 code will most likely not cause any issues at all with your car except a check engine light on the dashboard. There could be a problem with the fuel pressure, though, which will cause performance issues with your engine. This can also cause damages to your engine in the long term.
When you see the P0193 code, you should drive to a workshop to fix it as soon as possible. Towing is most likely not required.
What repairs can fix the P0193 code?
- Replace fuel pressure sensor
- Clean fuel pressure sensor connector plugs
- Repair fuel pressure sensor wirings
- Replace fuel pressure regulator vacuum hoses
- Replace fuel pressure regulator
- Replace Engine control unit
Common P0193 Diagnosis mistakes
The most common mistake when diagnosing the P0193 code is starting with fuel pressure related issues.
In most cases, the P0193 code is related to a faulty fuel pressure sensor signal caused by a faulty sensor. In some rare cases, it can be a problem with too high fuel pressure.
Recommended Tools for Diagnosis
- Diagnostic OBD Scan Tool
- Basic Hand Tools
- Auto Repair Manual
- Electrical Contact Cleaner
- Fuel Pressure Gauge
How to diagnose the P0193 Trouble Code
This is how a professional would diagnose the P0193 code. If you do not have the knowledge or do not have the right tools, you may have difficulty following this guide.
- Connect an OBD2 scanner and check for other related trouble codes.
- Check the fuel pressure signal in live data from your diagnostic tool on idle. Check if the pressure value changes while you rev up. If it stays still, it is most likely a faulty circuit to the sensor. If it moves but is too high related to the RPM, you most likely have a broken fuel pressure regulator or the vacuum hoses to it. Replace if necessary.
- Remove the connector plug from the fuel pressure sensor and check for any signs of corrosion.
- Check the wirings visually for any noticeable damages.
- Measure the fuel pressure sensor using the measuring diagram from your repair manual for your specific car model. Replace sensor if faulty.
- Do the same measurement towards the sensor from the engine control unit plug. Repair wirings if you get any strange values from there – but the signals are okay when measuring on the sensor.
- Manually check the fuel pressure and replace the fuel pressure regulator or vacuum hoses if the pressure is too high.
- Replace the fuel pressure sensor even if you got an accepted test.
- Replace engine control unit.
Estimated Cost of Repair
Here is a list of some common repairs associated with the P0193 code. The prices include labor and parts costs but do not include diagnosis costs.
- Fuel pressure sensor replacement – 40$ to 100$
- Fuel pressure sensor wiring repair – 20$ to 70$
- Fuel pressure regulator replacement – 50$ to 150$
- Fuel pressure regulator hose replacement – 10$ to 30$