汽车专业实用英语 作者 陈晟闽 15-Diagnosing Drivelines.ppt

Objectives Listen to the driver’s complaint, road test the vehicle, and then determine the needed repairs. Diagnose unusual fluid usage, level, and condition problems. Replace automatic transmission fluid and filter. Objectives Diagnose electronic control systems and determine needed repairs. Conduct preliminary checks on EAT systems and determine needed repairs or service. Perform converter clutch system tests and determine needed repairs or service. Objectives Inspect, test, and replace electrical/electronic sensors. Inspect, test, bypass, and replace actuators. Diagnose noise and vibration problems. Diagnose hydraulic and vacuum control systems. Objectives Perform oil pressure tests and determine needed repairs. Inspect and adjust external linkages. Describe the basic steps for overhauling a transmission. Transmission Identification Typical transmission identification tag locations Causes of Transmission Problems Poor engine performance Hydraulic system problems Mechanical malfunctions Electronic failures Improper adjustments Fluid and Filter Change Change the fluid and filter whenever there is an indication of oxidation or contamination. Periodic fluid and filter changes are also part of the preventative program for most vehicles. The kilometre interval recommended depends on the type of transmission. Change the fluid with the engine and transmission at normal operating temperature. Fluid Colour Diagnosis Red or pink Is normal fluid colour. Dark brown or black Fluid has been overheated. Milky colour Fluid has been mixed with engine coolant. Note: Colour cannot be used to diagnose synthetic fluids. Common Sources of Fluid Leaks Oil pan seal Transaxle rear cover and final drive cover Extension housing seal Speedometer drive seal Electrical switches Case porosity Sources of Transaxle Fluid Leaks Transmission Cooler Inspection Check the engine cooling system. Inspect the fluid lines between the cooler and transmission. Inspect the engine coolant for signs of transm