In this article you will find the information you need to solve the P0190 code in the fastest and most cost-effective way. Learn about the symptoms, causes, and the quickest ways to repair this code.
What does the P0190 code mean?
Code P0190 is triggered when the engine control unit receives a faulty signal from the fuel rail pressure sensor. It is a generic OBD2 code, i.e. it applies to all makes and models from around the year 2000 onwards, and is valid for diesel, gas, and other fuel types on the market.
The P0190 code is mainly an electrical fault in the fuel pressure sensor on most vehicle models, but on some models, the P0190 code can be triggered if the fuel pressure is also faulty. You should always start by checking your fuel pressure with a manual fuel pressure tester.
The engine control unit has a range of the fuel pressure sensor signal at a given RPM, boost pressure, etc. If the fuel pressure sensor signal is outside the recommended range, the code P0190 is triggered and stored.
The most common symptom of the P0190 code is just a check engine light that lights up, and you will have no other symptoms if it is a sensor problem. Since this fault code could mean both a sensor problem and a fuel pressure problem, you may have other symptoms. If you have a sensor problem, the engine control unit uses the default values for the sensor, and you may only see one indicator light for the engine.
- Check Engine Light / Service Engine Soon Light
- Engine will not start
- Hard starting condition / Long cranking time
- Engine makes sudden stops
- Lack of Power
- Limp mode
- Rough Idle
The most common cause is a faulty fuel pressure sensor or faulty wiring, but as I mentioned earlier, it can also be a fuel pressure problem, depending on the car you have. To diagnose this problem, you should always check your fuel pressure.
- Damaged fuel pressure sensor (Most common)
- Faulty wirings to fuel pressure sensor
- Corrosion/bad connection in the fuel pressure sensor connector plug
- Low fuel level
- Bad fuel pump relay
- Bad fuel pump
- Faulty fuel pump wirings
- Clogged fuel filter
- Faulty fuel pressure regulator
- Faulty vacuum hose to the fuel pressure regulator
- Faulty engine control unit (Rare)
- Replace fuel pressure sensor
- Clean the connector plug to the fuel pressure sensor
- Repair faulty wirings
- Fill tank level
- Check your fuel pump pressure
- Check fuel pump
- Replace fuel pump relay
- Replace fuel filter (If low fuel pressure)
- Fix vacuum leaks (If low fuel pressure)
- Replace fuel pressure regulator (If low fuel pressure)
- Replace engine control unit (Rare)
P0190 Troubleshooting Table
|Code||Description||Common Causes||Possible Solutions|
|P0190||Fuel Pressure Sensor – Circuit Malfunction||Damaged fuel pressure sensor
Faulty wirings to fuel pressure sensor
Bad connection in the fuel pressure sensor connector plug
Low fuel level
Bad fuel pump relay
Bad fuel pump
Faulty fuel pump wirings
Clogged fuel filter
Faulty Fuel pressure regulator
Faulty Vacuum hoses to the fuel pressure regulator
Faulty ECM/PCM (Rare)
|Replace fuel pressure sensor
Clean the connector plug to the fuel pressure sensor
Repair faulty wirings
Fill tank level
Check your fuel pump pressure
Check fuel pump
Replace fuel pump relay
Replace Fuel filter
Fix Vacuum leaks
Replace Fuel pressure regulator
Replace Engine control unit (Rare)
How to diagnose the P0190 code
This is a guide to how a professional automotive technician would diagnose this problem. You may need some knowledge as a car electrician and the necessary tools. I’m sure you can get some good information from this, even if you have little knowledge of car mechanics. You should always connect a car battery charger when troubleshooting your vehicle. A low voltage can trigger other, unrelated fault codes that may confuse your troubleshooting. In the worst case, a low voltage can also cause damage to your car’s electronics. This guide may differ slightly between car models. This guide is mainly intended for gasoline engines, as some diesel engines operate at very high pressure and may require special tools to check the fuel pressure.
Connect a car battery charger
Start by connecting a car battery charger to your car. Make sure it charges your car as it should. I would recommend a car battery charger over 4 amps otherwise you might discharge your battery when you have the ignition on.
Connect your OBD2 scanner
Connect your OBD2 scanner to your vehicle. Check the P0190 code. Clear the code and recycle the ignition and start the vehicle (if possible) to see if it comes back directly. Go to Live Data and check the value of the fuel pressure sensor. If the car does not start and you get a fuel pressure value of 0 bar, there is most likely a fuel pressure fault.
Locate your fuel pressure sensor
Locate the fuel pressure sensor. Once located, check the connector plug for corrosion or other damage. If possible, check the wiring. Now you should measure the wires with a digital multimeter. Fuel pressure sensors vary greatly depending on the vehicle model and you should find the correct wiring diagram beforehand. But normally there is a 5-volt power line, a ground line, and a signal line. You can check if you get 5 volts and ground from the engine control unit when the ignition is switched on. If you do not get them, check the cables.
If you find a circuit diagram for your fuel pressure sensor, you can measure the resistance at the pins to see if there is a short circuit or open circuit in the sensor.
Check the fuel pressure (Petrol)
The most important task in this troubleshooting is to check the fuel pressure. To check the fuel pressure, you will need a manual fuel pressure tester with the correct adapters to fit your fuel rail or fuel hose. Have a friend check the fuel pressure while you cycle the ignition. The fuel pump should normally prime about 10 seconds after you turn on the ignition. Start your car to check the fuel pressure.
If you get no fuel pressure
If you are not getting fuel pressure, you should diagnose the following parts:
- Fuel pump
- Fuel pump relay
- Fuel pump wirings
- Fuel filter
- Fuel pressure regulator
- An internal leak inside fuel tank on the fuel pressure hose
Recommended Tools to Fix P0190
- Read the trouble code memory: FOXWELL NT301 Scan Tool. For advanced troubleshooting, you may need a more advanced code scanner.
- Car battery charger: NOCO Genius G3500 6V/12V Smart Battery Charger
- To measure the wires/fuel pressure sensor: Digital multimeter
- Checking your fuel pressure: Manual Fuel Pressure Tester
If you have any further questions about the P0190 code, please comment below and I will answer you as soon as possible. If you have further questions about the car, feel free to ask us on our homepage.