P0455 Jeep Grand Cherokee. Obd2 code p0455 jeep definition: P0455 indicates that there is a large leak in the evaporative emission control system (evap).
Having fuel in the leak detection pump indicates a failure on the vapor valve on the fuel tank or a bad habit of topping off the fuel tank too much to a point it's pouring out of the filler neck.
It means a large leak has been detected. Related vehicles have similar information. It means a large leak has been detected. 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.