METHOD FOR DIAGNOSING FAULT WITHIN A FUEL VAPOR SYSTEM

摘要

A method for diagnosing a fault within a evaporative emission control system of an automotive vehicle. The method monitors the carbon canister temperature during a system leak test. The leak test here is undertaken with the engine running, and engine vacuum is employed to evacuate the EVAP system. If the evacuation succeeds in reaching a target vacuum, and a temperature gain in the canister is observed, then the system infers proper system operation. Failure to achieve a target vacuum causes the system to determine a likely cause of the failure based on the temperature response of the carbon canister.

主权项

1. A method for diagnosing a fault in an evaporative emission control system, comprising:
during a system leak test, monitoring carbon canister temperature; upon identifying a failure to achieve a target vacuum during a leak test, determining the carbon canister temperature change during the test; and inferring a likely cause of the failure based on a comparison of the temperature change and predetermined data.