Auxiliary Emissions ControlOBD2 Codes

P0452 – Meaning, Causes, Symptoms, & Fixes

Reading Time: 3 minutes


Code P0452 Definition

The evaporative pressure sensor or fuel tank pressure sensor has a low voltage signal.

What Does P0452 Mean?

The evaporative emission control (EVAP) system prevents fuel vapors from escaping into the atmosphere. This system stores the vapors in a charcoal canister and purges the vapors into the engine to burn them. The EVAP system pressure is checked by either an EVAP pressure sensor or a fuel tank pressure sensor (depending on your manufacturer). When ambient air temperatures go up this pressure goes up. When the Engine Control Module (ECM) purges the stored fuel vapors the pressure goes down. When code P0452 is triggered the ECM has detected an abnormally low voltage for an extended period of time. This can be caused by a faulty sensor, wiring or an EVAP system leak. 

What Are The Symptoms Of Code P0452?*

  • Check Engine Light
  • Possible fuel vapor smell

*No noticeable adverse conditions in some cases

What Is The Cause Of Code P0452?

  • Faulty Evap Pressure Sensor 
  • Faulty Fuel Tank Pressure Sensor
  • Loose/leaking gas cap
  • Cracked evaporative line
  • Leaking evaporative seals
  • Open/shorted wiring
  • Poor connection at sensor

How Serious Is Code P0452?- Low

This trouble code doesn’t affect how the car runs but does cause excessive emissions. In rare cases, you may smell a fuel vapor smell. Driving with this code won’t damage anything, but it is recommended to repair it to get your vehicle back to optimum running condition.

Code P0452 Common Diagnosis Mistakes

Replacement of parts without checking for a loose gas cap. 

Tools Needed to Diagnose:

  • FIXD
  • Basic Hand Tools
  • Vehicle Specific Service Manual
  • EVAP smoke machine leak checker
  • Multimeter

How To Diagnose And Repair Code P0452?

Difficulty of Diagnosis and Repair (3 out of 5)

  1. Check to see if there are any other codes along with P0452 and clear your Check Engine Light with FIXD. If there are other EVAP codes stored, they may be linked. Compare diagnostic steps to see if you have a shared failure.
  2. Check the freeze frame data in order to pinpoint the issue.
  3. Check your gas cap to see if it is loose or damaged.
  4. If your gas cap is loose, tighten it and clear the code.
  5. Inspect your gas cap for physical damage or deterioration. However, it should be noted that damage to the gas cap or deterioration of its components is not always noticeable. If your gas cap was not loose and you do not see any indications of failure, try replacing the gas cap anyway and clearing the codes. Gas caps are relatively inexpensive and are often the fix for code P0452.
  6. If the fuel cap didn’t fix it, perform an EVAP system leak check:
  7. Pinch off the vent tube to the EVAP Vent Control Valve.
  8. Pressurize the EVAP system with an EVAP smoke machine leak checker.
  9. Check to see if you see any smoke leaking out from any hoses or seals. If there are any leaks, repair leaks, clear the check engine light, and check to see if the concern is resolved.
  10. If you found no leaks, check the signal voltage at the EVAP pressure sensor or fuel tank pressure sensor (depending on your manufacturer), and compare it to your vehicle’s specifications. Now apply a slight amount of pressure, using the smoke machine tester, and monitor the voltage of the pressure sensor. Compare it to the manufacturer’s spec; if it’s out of specification, replace the sensor. 

Estimated Cost of Repair

For error code P0452, one or more of the below repairs may be needed to solve the underlying issue. For each possible repair, the estimated cost of repair includes the cost of the relevant parts and the cost of labor required to make the repair. 

  • Gas Cap $20-$60
  • EVAP Line $20-$100
  • EVAP Pressure Sensor $280-$330
  • Fuel Tank Pressure Sensor $280-$330


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