Fault code P018B is called “Fuel Pressure Sensor “B” Circuit Range/Performance” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.
Technical description and explained code P018B
This Diagnostic Trouble Code (DTC) is a generic powertrain code. Error P018B is considered a general code because it applies to all makes and models of vehicles. Although the specific repair steps may vary slightly from model to model.
Some modern vehicles equipped with high pressure fuel injection systems have two fuel pumps. The low pressure pump (LP) is located in or near the fuel tank and the high pressure pump (HP) is located on the engine.
Typically, the low-pressure pump operates at 2.4-5.0 atmospheres. And the high pressure pump uses mechanical power, usually from the camshaft. So that once the pressure is increased, the fuel is fed to the direct injection injectors.
If the ECM detects that the incoming signal from the fuel ramp pressure sensor does not match the one supplied to the engine. This could be a mechanical failure or an electrical circuit malfunction, depending on the vehicle manufacturer, fuel type, and fuel system.
The MIL (Malfunction Indicator Light) will then illuminate and a DTC (Diagnostic Trouble Code) will be written in memory. The error P018B is defined as a discrepancy in the operating range of the “B” fuel pressure sensor.
Symptoms of vehicle malfunctions
The main signal that an error P018B has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.
It can also be warning signs such as:
- Check engine control lamp on the control panel will light up (the code will be written to the ECM memory as a fault).
- The engine stalls or starts badly.
- Unstable engine operation when accelerating the vehicle.
- Bad acceleration of the vehicle.
- Loss of power.
- Increased fuel consumption.
- In some cases the engine fails completely.
The severity of error P018B is very high, the cause should be eliminated as soon as possible. Since when it appears, the car may have problems not only with drivability, but also complete engine failure.
Factors that can cause this error code
The error code P018B can mean that one or more of the following problems have occurred:
- A damaged fuel pressure sensor (FPS) is the most common cause.
- Damaged connector or broken circuit to the sensor.
- Excessive resistance in electric circuit.
- High fuel pressure.
- Low fuel pressure.
- Vacuum leakage.
- Low or no fuel level.
- Sometimes faulty PCM module is the cause.
How to fix or reset OBD-2 code P018B
Some suggested steps for troubleshooting and fix the error code P018B:
- Read all stored data and error codes with an OBD-II scan tool.
- Clear the error codes from the computer memory.
- Test-drive the vehicle to see if error P018B appears again.
- Visually inspect the connector and electrical wires for damage. If present, repair the damaged areas.
- Check the resistance to make sure it is within tolerance.
- Replace the faulty fuel pressure sensor (FPS).
- Test the engine control module (ECM).
Diagnose and repair of problems
Starting troubleshooting P018B, locate pressure sensor on fuel manifold, once found, visually inspect connectors and wiring. Look for scuffs, exposed wires, burn marks, or melted plastic. Disconnect the connectors and carefully inspect the terminals inside. Inspect them for rust and other damage.
Clear the P018B diagnostic trouble code from the memory and see if it comes back. If it is gone, the problem was in the wires or connections. If the fault code returns, we will need to test the sensor and associated circuits.
Checking the pressure sensor connection
Using a digital voltmeter, check the 5V power supply signal circuit going to the sensor. Red wire to the 5 V supply circuit, black wire to ground. If 12 volts is present on the sensor, then as it should be 5, repair the wiring from the PCM to the sensor. This looks like a short or a faulty PCM.
If all is good on the signal circuit, make sure the ground on the FPS sensor is normal. Connect the test lamp to the plus side of a 12 volt battery, and touch the other end of the test lamp to the ground on the FPS sensor ground.
If the indicator lamp does not light up, this indicates a faulty circuit. If it lights up, jiggle the wiring harness going to the FPS sensor. To see if the check lamp blinks, this could indicate an intermittent connection.
When you do these tests, you will most likely find a problem with either the wiring or the sensor, which will need to be replaced. But if you still get a P018B code after fixing it, that could indicate a PCM failure.
On which vehicles does this problem occur most frequently
Fault code P018B can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:
- Cadillac (Escalade)
- Chevrolet (Camaro, Captiva, Impala, Silverado, Tahoe)
- Ford (Escape)
- Opel (Astra, Insignia)
Fault code P018B can sometimes be found with other errors. The most common are the following: P018A, P018C, P018D, P018E.