Evaporative Emission Control System prevents leaking of fuel vapors into the atmosphere by absorbing and storing them in the charcoal container. Absorbing action are provided by charcoal pellets. An OBDII Enhanced EVAP systems can purges vapors back to the engine to be injected to cylinders by standard methods.
In a simple explanation, there is a component called PCM and it responsible for testing EVAP system. He doing various tests into the system, operating in different time sets. The key how PCM knows that leaks occurring – is the pressure checking. An object to perform level of pressure testing is a fuel tank, and subject is the fuel tank pressure sensor, operated by PCM. The last frequently asking the sensor and if the low pressure level signal returned – P0456 error occures. It should be noted that this error code may not appear immediately, but only after the Powertrain Control Module (PCM) twice detects an error.
What are the symptoms of error P0456?
Causes of Error P0456
How does a mechanic diagnose error P0456?
When diagnosing this error code, the car mechanic always performing the following:
General errors, when the code P0456 has got
How Serious is Error P0456?
What repair can fix the error P0456?
Additional comments for resolving error P0456
It should be noted, that error P0456 does not appear in all vehicles. If this error still appears in your vehicle and the Check Engine indicator lights up, the most common reason for its occurrence is damage to the fuel tank cap, purge valve, or ventilation valve, resulting in a very small leak.