Systems and methods for diagnosing components in a vehicle evaporative emissions system

A system for a vehicle, comprising:

• a fuel vapor canister positioned in an evaporative emission system;
• a fuel tank positioned in a fuel system;
• an engine with an intake manifold and an exhaust manifold;
• a canister purge valve positioned in a purge conduit between the fuel vapor canister and the intake manifold;
• a fuel tank isolation valve positioned in a conduit between the fuel tank and the fuel vapor canister;
• a canister vent valve positioned in a vent line between the fuel vapor canister and atmosphere;
• a canister heating element, coupled to and/or within the fuel vapor canister;
• a secondary bleed canister positioned in the vent line between the fuel vapor canister and the canister vent valve;
• a hydrocarbon sensor positioned in the vent line between the fuel vapor canister and the secondary bleed canister;
• and
• a controller, storing instructions in non-transitory memory that, when executed, cause the controller to:
• responsive to an indication of completion of a refueling event:
• in a first condition, purge fuel vapors stored in the fuel vapor canister to the intake manifold of the engine for combustion by commanding open the canister purge valve and the canister vent valve without prior activation of the canister heating element;
• in a second condition, purge fuel vapors stored in the fuel vapor canister to the intake manifold of the engine for combustion by commanding open the canister purge valve and the canister vent valve after activation of the canister heating element;
• and
• diagnose whether the canister heating element and the hydrocarbon sensor are functioning as desired in the second condition, but not the first condition;
• where the first condition is commenced prior to the second condition after completion of the refueling event.