() [] a device or system that is used to identify a problem, an illness or a problem with a piece of equipment or software诊断工具／系统◆a detailed, in-depth diagnostic of the company对这公司的详细深度诊断◆Your car is hooked up to a computer to run diagnostics.将你的汽车连接到电脑上以进行诊断。a message on a computer screen giving information about a fault诊断信息（提示计算机的错误）