日产汽车EOBD培训ppt课件.ppt

E-OBD介绍 目标 E-OBD介绍 E-OBD介绍 E-OBD 诊断项目 E-OBD 特性 E-OBD 诊断传感器 标准状态检查 ECTS（发动机冷去温度传感器）例子 合理性检查的例子 功能检查 检查 E-OBD 诊断信息 双行程诊断逻辑 燃油系统状态 计算负荷值 发动机冷却温度 短期燃油修正 长期燃油修正 发动机转速 车速 绝对压力 节气门绝对位置传感器 基本喷油时间 进气温度 模式 2 由于系统故障造成开环。这表示一个关键部件或系统失效。 ■模式 3 由于行驶条件导致开环，例如发动机负荷高。 ■模式 4 采用氧传感器反馈的闭环，行驶条件和系统工作正常。. 模式 5 由于发动机不满足闭环条件导致开环。多数情况下，这表示发动机还未达到工作温度。 三元催化器功能 三元催化器 (TWC) 废气再循环系统 (EGR) 蒸发控制系统 (EVAP) 曲轴通风阀 (PCV) EGR 系统组成 Discuss: Hydrocarbons (HC) are unburned fuel vapors caused by incomplete combustion or engine misfires. These produce photochemical smog when exposed to sunlight. (Also on slide 8) Carbon Monoxide (CO) is an odorless and colorless toxic gas. It is formed when there is not enough oxygen to support combustion, which makes it a useful indicator of a RICH air/fuel mixture. Carbon Monoxide can cause illness and/or death. (Also on slide 7) Oxides of Nitrogen (NOx) are created by high combustion pressures and temperatures. They contribute to photochemical smog and can cause lung tissue damage. (Shown separately on slide 6) Being able to analyze the content of a vehicle’s exhaust will help you to diagnose and repair ECCS and emissions control problems more efficiently. ?Review typical O 2 sensor voltage pattern ?Ask technicians how the O2 sensor works. ?Normal operation should have a voltage pattern the fluctuates between 0 –0.3 volts and 0.6 –1.0 volts more than five times in ten seconds ?Show a rapid rate of voltage increase and decrease, verifying good response When monitoring conditions are met, the catalyst monitor measures the inversion of the front and rear O2 sensor. After determining the specific amount of O2 sensor inversion, a front-to-rear O2S inversion ratio is calculated. If this ratio exceeds the threshold, the monitor judges the catalyst is malfunctioning or deteriorated. If this repeats during two consecutive drive cycles, the monitor illuminates the MIL and stores a DTC. The catalyst mo