Engine-Codes - Generic - P0456

P0456 Code - EVAP Control System Leak Detected Very Small Leak

- Code Popularity: 145,294 Views
- Repair Importance Level: 1/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC P0456?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Missing or loose fuel cap
  • Incorrect fuel filler cap used
  • Fuel filler cap remains open or fails to close
  • Foreign matter caught in fuel filler cap
  • Evaporative Emission (EVAP) canister or fuel tank leaks
  • Evaporative Emission (EVAP) system hose leaking
  • Fuel tank leaking

Code Tech Notes





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How to Fix the DTC P0456?

Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

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What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P0456 code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

When is the Code Detected?

Evaporative Emission (EVAP) control system has a very small leak such as loose fuel filler cap.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)
  • A noticeable fuel odor may result from fuel vapor release

What Does the P0456 Code Mean?

This diagnosis detects leaks in the Evaporative Emission System (EVAP) purge line using engine intake manifold vacuum. If pressure does not increase, the Engine Control Module (ECM) will check for leaks in the line between the fuel tank and EVAP canister purge volume control solenoid valve under the following vacuum test condition.
The vacuum cut valve bypass valve is opened to clear the line between the fuel tank and the EVAP canister purge volume control solenoid valve. The EVAP canister vent control valve will then be closed to shut the EVAP purge line off. The EVAP canister purge volume control solenoid valve is opened to depressurize the EVAP purge line using intake manifold vacuum. After this depressurization is implemented, the EVAP canister purge volume control solenoid valve will be closed.
P0456 Code - EVAP Control System Leak Detected Very Small Leak

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Code P0456 Information for Specific Makes

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