fuel pressure sensor

P0193 Trouble Code – Fuel Rail Pressure Sensor Circuit High Input

In OBD2 Trouble Codes by Josh S1 Comment

fuel pressure sensor

What Does the P0193 Code Mean?

The P0193 code indicates that there exists a problem with Fuel Rail Pressure Sensor. When the powertrain control module (PCM) detects that the fuel rail pressure is outside the predetermined range, it generates the P0193 code.
The PCM relies on the fuel rail pressure sensor to deliver the correct information so that it can control the fuel injectors and deliver the required amount of fuel to ensure efficient combustion. The fuel rail pressure (FRP) sensor’s resistance varies with the pressure. As the pressure increases, the sensor’s resistance increases and when the pressure decreases, the resistance also decreases. This change in resistance affects the voltage across the sensor’s terminal and provides a signal to the PCM. A faulty fuel rail pressure transmits an incorrect signal to the PCM causing the P0193 code to generate.

P0193 Symptoms

  • Check engine light illuminates
  • The engine does not start at all
  • Difficulty in acceleration
  • The engine takes a longer time to start
  • Lack of power
  • Fuel consumption increases
  • An abnormal smell coming from the exhaust pipe

 

Possible Causes

  • Fuel rail pressure (FRP) fails
  • Faulty fuel pump
  • Clogged fuel filter
  • Damaged or corroded wiring
  • Vacuum leak
  • Faulty fuel pressure regulator

Possible Solutions

  • Ensure the fuel tank is not empty
  • Repair the broken connections
  • Replace the dirty/contaminated fuel filter

 

How to Diagnose the P0193 Code?

Plug in the Car Battery Charger

When diagnosing the P0193 code, your vehicle’s engine should be running. This leaves a risk of the battery getting discharged and may result in additional trouble code to be generated. To avoid this problem, buy a Car battery chager and keep it connected at all times when diagnosing the trouble code.

Connect the OBD2 Scanner

An OBD2 scanner is required to read the information contained in the trouble code. There are generally two types of OBD2 scanner: a regular code reader which is available at a low price and an expensive advanced scan code that also includes a number of different features.
You can also use a multimeter to measure the resistance but it requires a lot of time and is not preferred.

Disconnect then Re-Connect the Car Battery

Sometimes the PCM does weird things which cause the sensors to malfunction. A simple way to fix this problem is by removing the negative terminal of the battery and then reconnecting it. This resets all the sensors in the car.

Check the Fuel Pump

To check if the fuel pump is functioning properly, listen to its noise when starting the car. If the car is unable to start but you can hear the fuel pump working, the fuel filter is probably clogged and needs replacement.

Check for Reference Voltage

If the above steps are carried out successfully, the next task is to test the reference voltage of the fuel rail pressure sensor. Start the ignition, then using a digital volt-ohmmeter, check the reading to see if it reads 5 volts. If the reading is not close to 5 volts, the connections need to be rechecked.

Check for Ground Wiring

A lot of times, the P0193 trouble code generates due to an improper ground wiring. To test the ground wiring, connect one end of the jumper cable to a good ground point on the engine and the other end on the negative terminal of the battery. Check the voltage reading before and after connecting the jumper cable to notice the difference. If you notice a better reading when the jumper wire is connected, a ground problem exists.

 

 

How to Replace the Fuel Rail Pressure Sensor?

If you prefer working on your car yourself, you can easily replace the fuel rail pressure sensor at home. However, if you have not performed a replacement procedure before, we suggest that you visit a professional mechanic.

Tool required:

  • Socket Wrench
  • Gloves
  • Cleaning cloth
  • Safety glasses

Step 1: Park the Car on a Flat Surface

Ensure that your car is parked on a flat surface with parking gear engaged.

Step 2: Disconnect the Car Battery

Open the hood and locate the negative terminal of the battery. Remove the negative terminal of the battery to ensure that there is no current in the circuit.

Step 3: Locate the Fuel Rail Pressure Sensor

You would have to remove the engine cover and look for the fuel rail pressure sensor. It can be found on the top center of the fuel rail.

Step 4: Remove the Sensor

Remove the fuel rail pressure sensor using a screwdriver or socket wrench. You might have to place a cloth towel over the port and a drip pan under the rail.

Step 5: Cleaning the Harness

Using an electrical cleaner, clean the harness surrounding the fuel rail sensor.

Step 6: Install a new Sensor

Install the new fuel rail sensor in its place and connect the harness. Make sure to tighten all the screws and bolts so that it remains firm in its place.

Step 6: Reconnect the battery terminal

Reconnect the negative terminal of the battery and start the engine.

 

Fuel Rail Pressure Sensor Replacement Cost

The average cost to replace the fuel rail pressure sensor is between $260 and $320. The labor cost comes around $200 and $250 while the part itself costs between $60 and $80. The pricing may vary depending on the vehicle and the mechanic’s labor cost.

 

Should I Repair the P0193 Trouble Code Right Away?

The P0193 trouble code should be fixed right away as it results in drivability issues. Ignoring the P0193 code for too long can cause damage to the engine and at some point, the vehicle will fail to start immediately.

 

Recommended Tools to Fix P0193 Code

Car battery charger
Digital multimeter to test voltage and resistance readings
OBD2 scanner to scan the trouble code. Check this website to find reviews about different OBD2 scanners: AutoZik Diagnostic Tools
Electric cleaner to clean to service the dirty sensor

 

Further Questions?

If the above-provided solutions do not help with the P0193 trouble code, reach us out by commenting below and we will get back to you at our earliest.

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Comments

  1. Hi Josh, 2007 Ford F150, crank no start. I have no 5 volt ref from PCM to fuel rail pressure sensor. It does share this5 volt ref with the power steering oil sensor. I have checked the wire from the PCM to the connector at the FRPs and its ok. Back probed the wire to the PCM, no voltage. I say no voltage but i checked it with a test light. I also have no codes. I have disconnected sensors to see if it will give an engine check light or code but none. There is communication though to the scanner/ code reader but says the EVAP is not supported.

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