Systems and methods for indicating canister purge valve degradation

Abstract

Methods and systems are provided for indicating whether a canister purge valve in a vehicle evaporative emissions control system is degraded. In one example, an air intake system hydrocarbon (AIS HC) trap temperature may be monitored during a refueling event, and responsive to an indication that the AIS HC trap temperature change is greater than a predetermined threshold, it may be indicated that the canister purge valve is degraded. In this way, diagnosis of whether a vehicle canister purge valve is degraded may be indicated without the use of engine manifold vacuum, and may be advantageous for vehicles configured to operate for significant amounts of time without engine operation, or without intake manifold vacuum.

Dependencies are inferred from the claim text.