Error Code P0452 is defined as Evaporative Emission Control System Pressure Sensor Low Input. This means there’s an ongoing problem in the fuel tank pressure sensor or evaporative pressure sensor, usually caused by a vacuum leak or loose fuel gap.

This error code is a generic trouble code, meaning it applies to all vehicles equipped with OBD-II system, especially those made since 1996 up to present. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model to another.


Error Code P0452 appears when the PCM (powertrain control module, also known as ECM or engine control module in other vehicle makes) has determined that the system pressure is lower than normal, indicating a problem in the system, not necessarily just in the sensor.

This error code is categorized as an emission system malfunction. The PCM depends on the fuel tank pressure sensor to detect fluctuations in the internal pressure of the tanks. Depending on the make of the vehicle, the sensor could be located in the fuel purge line, which comes from the fuel module on the top of the fuel tank, or the tank itself.

The sensor is provided for the emission control strategy. The fuel tank tends to build fuel vapor pressure when the temperatures are high and a vacuum, when under a load. If the detected voltage by the PCM is outside the manufacturer’s set parameters, then it activates the Error Code P0452, indicating a fault.

Other related codes include P0450, P0451, P0453, P0454, P0455, P0456, P0457, P0458, and P0459.

Common Symptoms

As with other error codes, P0452 activates the Check Engine light and registers the code to the vehicle’s system memory. Other than the Check Engine light being illuminated, this code doesn’t cause any noticeable symptoms or drivability problems.

Possible Causes

Possible common causes for this code include:

  • Defective fuel tank pressure sensor
  • Defective fuel tank pressure sensor wiring
  • Loose fuel gap
  • Defective purge control solenoid
  • Damaged or clogged charcoal canister
  • Vacuum leak

How to Check

Like most EVAP-related error codes, mechanics start their diagnosis of this code by inspecting the fuel cap, retightening the cap, and then clearing the code then reset the engine computer before taking the vehicle to a test drive to see if the code returns.

If the code doesn’t return, then it could just be a cause of the loose gap.

If the code returns, however, then the fuel tank pressure must be causing the problem.

To test further, the technician will use an OBD-II scanner to check the fuel tank pressure readings and see if the engine computer is reading vacuum from the sensor. If not, then the wiring from the sensor must be checked to ensure there is no communication error, before replacing the pressure sensor.

How to Fix

Error Code P0452 is pretty easy to fix. In many cases, it could just be a case of loose fuel cap, which means tightening the fuel cap will fix the problem. In other cases, it would need repair or replacement of the fuel tank pressure sensor and repair of the damaged wiring in the fuel tank pressure sensor.

Error Code P0452 as with most EVAP-related codes increases the emission of the vehicle but doesn’t really cause drivability or performance issues for the vehicle.

The most common mistake in addressing this code, however, is replacing the pressure sensor when tightening the fuel cap can simply fix the problem.