What Does The P0190 Code Mean?

The P0190 trouble code gets stored in the engine control unit’s trouble code memory when there is a problem with the circuit to the fuel rail pressure sensor.

This can be caused by a few different things, and in this article, you will learn everything you have to know about the P0190 code.

Code P0190 Definition

Fuel Rail Pressure Sensor – Circuit Malfunction

What does the P0190 code mean?

The P0190 trouble code indicates that there is an issue in the circuit between the engine control unit and the fuel rail pressure sensor. The fuel rail pressure sensor’s function is to measure the fuel pressure in the fuel rail and then report it to the engine control unit.

P0190 Trouble Code Symptoms

When the P0190 code appears, the engine control module will use a simulated value of the fuel pressure instead of the sensor’s given pressure. This means you will probably not notice any other symptoms than a check engine light on your dashboard.

Here are the symptoms of the P0190 code:

Check Engine Light / Service Engine Soon Light
The engine will not start
Hard starting condition / Long cranking time
The engine makes sudden stops
Lack of Power
Limp mode
Rough Idle

Causes of the P0190 Code

There are actually not that many things that can cause the P0190 code. It tells us that there is a problem with the electrical circuit to the sensor, which means something is wrong with any of these things.

The following issues could cause the P0190 code:

Faulty Fuel Rail Pressure Sensor
Faulty Wires to the rail pressure sensor
Corrosion in connector plugs to the rail pressure sensor.
Faulty ECU

How serious is the P0190 Code?

Medium – When this trouble code appears, the car will often set itself into limp mode. This will cause the RPM and power to be limited, so you can’t put hard pressure on the engine. The car engine will most likely not stall because of this trouble code, though.

The P0190 can damage your engine in the long run, and it should be repaired as fast as possible.

What repairs can fix the P0190 code?

Replace Fuel Rail Pressure Sensor
Clean Fuel Rail Pressure Sensor Connector Plugs
Repair Fuel Rail pressure Sensor Wirings
Replace Engine control unit

Common P0190 Diagnosis mistakes

A common diagnosis mistake is to start looking for problems regarding your car’s fuel pressure like fuel pumps or fuel filter.

This trouble code tells us that there is an issue with the circuit and not that there is a problem with the fuel pressure.

Another mistake is to replace the fuel pressure sensor without checking the wirings.

Recommended Tools for Diagnosis

Diagnostic OBD Scan Tool
Multimeter
Basic Hand Tools
Auto Repair Manual
Electrical Contact Cleaner

How to diagnose the P0190 Trouble Code

The diagnosis process of the P0190 code is pretty straightforward. You may need some special tools to procedure this diagnosis.

Connect an OBD2 scanner and check for related trouble codes.
Locate the fuel pressure sensor and check the connector plug for any corrosion or other damages.
Find the recommended ohm values of the fuel pressure sensor for your car engine model, and then measure the ohm value. If there is an open circuit or wrong values at the given fuel pressure, replace the sensor.
Visually inspect the wirings to the fuel pressure sensor for any damages.
Remove the connector plug from the engine control unit, and measure the sensor’s ohm value from there for any open circuit or resistance problems. Repair wirings if faulty.
Replace the fuel pressure sensor even if your tests showed it was correct.
Replace the engine control unit.

Estimated Cost of Repair

Here are some repairs commonly associated with the P0190 code. The prices include labor and part costs, but do not include diagnosis costs.

Replace fuel pressure sensor – 30$ to 60$
Repair fuel pressure sensor wirings – 30$ to 70$
Replace engine control unit – 1000$ to 2000$

How do I fix code P0190?

The fastest way to fix the P0190 trouble code is by checking the fuel rail pressure sensor’s electrical circuit. This includes the sensor itself, its connector, and the wiring that goes to the ECU. In simple words, this code will get triggered when the car’s ECU is not getting the signal from the said sensor. To pinpoint the faulty component, you’ll, in most cases, only need an OBD2 scanner and a multimeter, which is used to measure the electrical resistance on the fuel rail pressure sensor’s connector.

Where is the fuel rail pressure sensor located?

As its name suggests, the fuel rail pressure sensor is located on the fuel rail, which is, in essence, a piece of a thick metal tube. In most cars, the fuel rail will be just near the cylinder head, on its intake side. The sensor in question will, in almost all cases, be the only electrical component on it.

Is It Safe To Drive With Code P0190?

While driving your car with the P0190 trouble code on, this is not recommended. This code is triggered when there is an error with the fuel rail pressure sensor or its wiring. Without the signal from it, the ECU will not be able to accurately adjust the air-fuel mixture. As a result, the engine’s performance may be decreased, and the vehicle may even go into limp mode. While it’s not very likely, the P0190 may even cause your car to stall, which can be dangerous in fast-moving traffic.

How Do You Clear Code P0190?

The only way to clear the P0190 trouble code is by accessing the vehicle’s diagnostic memory, and this can only be done using an OBD2 scan tool, which is – among other diagnostic purposes – used to erase any error codes. But before doing this, you’ll have to find out what’s causing the problem in the first place and fix it. Otherwise, the P0190 trouble code will keep coming back.

The fuel delivered to the engine and its injector is under pressure, and the amount of pressure may vary depending on the driving conditions. To achieve optimum engine performance, the vehicle’s ECU needs to accurately know how high is the fuel pressure at any given moment.

This is what the fuel rail pressure sensor is for, which is fitted on the fuel rail and measures the fuel pressure inside it. But when the ECU senses an electrical problem with the signal coming from this sensor, it will trigger a P0190 trouble code. This can be caused by the sensor itself, its connector, and the wiring that goes to the ECU.