Replacing Fuel Tank Pressure Sensor In Chevy Silverado: Step-By-Step Guide

The fuel tank pressure sensor in a Chevy Silverado helps control fuel vapour emissions by alerting the car's computer of any drops in pressure. This sensor is connected to the vehicle's ECU and illuminates the check engine light when it detects a leak. While it is recommended that the sensor be replaced by a professional technician, it is possible to do it yourself. The process involves raising the vehicle, removing the fuel tank off-road shield, loosening the filler neck hose clamp, and disconnecting the fuel tank filler neck, tank straps, insulator strips, and electrical connections. The sensor can then be pried out and replaced.

Fuel tank pressure sensor function

The fuel tank pressure sensor is an integral part of your car's evaporative emissions system, also known as EVAP. The EVAP system is designed to keep all gasoline vapours within your car's fuel system. The fuel tank pressure sensor helps control fuel vapour emissions by constantly reading the pressure in the fuel tank and alerting the car's computer if there's a drop in pressure.

The sensor is connected to the engine computer, and when it detects a leak, or if the sensor itself fails, it illuminates the "check engine" light. The sensor can detect a leak from the gas cap or anywhere in the system, including the lines. It does this by monitoring both positive and negative pressure inside the fuel tank.

The fuel tank pressure sensor is also used to test the vent valve and purge valve operation. When the valves are open, the pressure sensor reads the fuel tank pressure and will note a drop in pressure. If it doesn't drop, the purge valve or vent valve may be faulty.

If the sensor itself is faulty, a technician will remove all connectors, clean the surface around the faulty part, and install a new sensor. The sensor cannot be repaired if it is faulty and must be replaced. Due to the risk of fire and the potential difficulty of diagnosis, EVAP system issues should be handled by a professional technician.

Fuel tank pressure sensor location

The fuel tank pressure sensor is attached to the fuel sending unit in the fuel tank.

For the rear tank, you will need to:

• Drain the fuel from the tank.
• Raise the vehicle.
• Remove the fuel tank off-road shield, if your model has one.
• Loosen the filler neck hose clamp at the fuel tank and disconnect the fuel tank filler neck from the tank.
• Support the fuel tank and remove the tank straps and insulator strips, if equipped.
• Lower the fuel tank.
• Disconnect the fuel feed and vapor hoses, as well as the electrical connections at the sender.

Now you should be able to access the fuel pressure sensor.

For the side tank, the sensor is located on the upper portion of the front of the tank assembly. To access it, you will need to:

• Drain the fuel from the tank.
• Raise the vehicle.
• Loosen the filler neck hose clamp and disconnect the fuel tank filler neck from the tank.
• Support the fuel tank and remove the tank straps and insulator strips, if equipped.
• Lower the fuel tank shield.
• Lower the fuel tank.
• Disconnect the fuel feed and vapor hoses.
• Disconnect the electrical connections at the sender.

Alternatively, if you have a 1999 Silverado extended cab with a short bed, it may be possible to replace the fuel tank pressure sensor without dropping the tank. This can be done by jacking up the rear end and placing jack stands under the axle tube. You may also want to remove the left rear wheel for more room.

Fuel tank removal

To remove the fuel tank of a Chevy Silverado, first, drain the fuel from the tank. Then, raise the vehicle and remove the fuel tank off-road shield, if it is equipped with one. Next, loosen the filler neck hose clamp at the fuel tank and disconnect the fuel tank filler neck from the fuel tank. Support the fuel tank and remove the tank straps and insulator strips, if equipped. Finally, lower the fuel tank and disconnect the fuel feed and vapor hoses, as well as the electrical connections at the sender.

If you have a side gas tank, the process is slightly different. After draining the fuel and raising the vehicle, you will need to loosen the filler neck hose clamp and disconnect the fuel tank filler neck. Support the fuel tank and remove the tank straps and insulator strips, if equipped. Lower the fuel tank shield and the fuel tank. Then, disconnect the fuel feed and vapor hoses, followed by the electrical connections at the sender.

Alternatively, if you are looking to replace the fuel tank pressure sensor without dropping the tank, you can try jacking up the rear end and placing jack stands under the axle tube. Removing the left rear wheel can also provide more room to work with. If needed, jack up the body on the driver's side as well. From there, you should be able to reach the fuel tank, fuel pump, electrical connectors, and fuel lines.

Sensor replacement

Firstly, drain the fuel from the tank. Then, raise the vehicle. If your Silverado is equipped with a fuel tank off-road shield, remove it. Loosen the filler neck hose clamp at the fuel tank and disconnect the fuel tank filler neck from the fuel tank. Support the fuel tank and remove the tank straps and insulator strips, if equipped. Lower the fuel tank. Disconnect the fuel feed and vapor hoses. Disconnect the electrical connections at the sender.

Now, you should be able to access the fuel pressure sensor, which is attached to the fuel sending unit in the fuel tank. Remove all connectors, clean the surface around the faulty part, and install a new sensor.

When replacing the sensor, ensure you are taking the proper precautions against fire hazards. It is also recommended that EVAP system issues are handled by a professional technician due to the risk of fire and the potential difficulty of diagnosis.

Troubleshooting

If you are experiencing problems with your Chevy Silverado, there is a chance that the fuel tank pressure sensor is faulty and needs to be replaced. Here is some troubleshooting advice to help you identify and fix the issue:

Symptoms of a Faulty Fuel Tank Pressure Sensor

The fuel tank pressure sensor plays an important role in reducing the environmental impact of your Chevy Silverado by detecting leaks in the fuel system and preventing fuel vapour emissions. If this sensor is faulty, you may experience the following issues:

• The check engine light illuminates, indicating an EVAP problem.
• A popping sound may accompany the check engine light due to the leak detection pump attempting to pressurize the fuel tank.
• Poor fuel efficiency.
• Difficulty starting the engine.
• Stalling.

Error Codes

If you have access to an OBD scanner, you can check for specific error codes that indicate a problem with the fuel tank pressure sensor. The most common codes are P018B for third-generation trucks and P0452 for older models.

Diagnosing the Issue

Before replacing the fuel tank pressure sensor, it is important to rule out other potential causes of the problem. For example, a bad seal on the gas cap or a broken fuel line could also affect pressure and trigger the error codes. Therefore, detailed troubleshooting is necessary to confirm that the sensor is indeed the issue.

Replacing the Fuel Tank Pressure Sensor

If you have identified that the fuel tank pressure sensor is faulty, you may need to replace it. This task can be challenging and should be approached with caution. Some people choose to remove the fuel tank to access the sensor more easily, but it is possible to replace it without dropping the tank. Here are the basic steps involved:

• Jack up the rear end of the vehicle and place jack stands under the axle tube.
• Remove the left rear wheel for more room.
• Optionally, jack up the body on the driver's side for additional space.
• Disconnect the harness from the sensor and remove the old sensor. This may require some twisting and pulling.
• Install the new sensor by first pushing in the rubber grommet, then lubricating the sensor nipple and gently pushing it into place.
• Reconnect the electrical plug or harness.

Frequently asked questions