| 主权项 |
1. A method for determining a flexible fuel ethanol concentration and detecting a hardware malfunction, comprising:
detecting whether a refuel event has occurred; and when occurrence of the refuel event is detected, performing a primary ethanol concentration and hardware malfunction determination, said primary ethanol concentration and hardware malfunction determination including:
detecting an air-fuel ratio during a pre-fuel mix period and learning the air-fuel ratio detected during the pre-fuel mix period as a current hardware reference value, the pre-fuel mix period being a period during which only flexible fuel which has not mixed with flexible fuel from the refuel event is being consumed by a vehicle engine;determining a hardware reference value difference between the current hardware reference value and a previous hardware reference value from an immediately preceding vehicle driving cycle occurring prior to the refueling event;when said hardware reference value difference is greater than or equal to a predetermined hardware reference value threshold, detecting a hardware malfunction; andwhen said hardware reference value difference is less than the predetermined hardware reference value threshold, detecting the air-fuel ratio during a post-fuel mix period following the pre-fuel mix period and learning an ethanol concentration based on the air-fuel ratio detected during the post-fuel mix period. |
