P0451 OBD-II：蒸发排放系统压力传感器/开关 OBD-II故障代码P0451是什么意思？
OBD-II代码P0451被定义为蒸发控制系统压力传感器范围/性能。
See_also: P2456 OBD II故障代码 代码P0451表示在EVAP监控器测试和/或车辆运行期间，蒸发压力传感器显示的压力变化值不符合规范。
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蒸发控制（EVAP）系统捕捉从燃油储存系统（如油箱、加注颈和油箱盖）蒸发的任何原燃油。 在精确的工作条件下（由发动机温度、转速和负荷决定），EVAP系统储存并清除这些捕捉到的燃油蒸气，使其回到燃烧过程中。 油箱压力传感器是一个跟踪任何正或负压力的装置。燃油箱压力传感器用于监测燃油存储或蒸发控制（EVAP）系统中的负压变化，并不断将压力信息传递给动力总成控制模块（PCM）。 燃油箱压力传感器位于燃油箱顶部或燃油泵和燃油表模块上或附近。
症状
- 发动机检查指示灯点亮
- 在大多数情况下，驾驶员不会注意到任何不利条件
- 在某些情况下，由于燃料蒸汽的释放，可能会产生明显的燃料气味。
触发P0451代码的常见问题
- 燃油箱发送装置故障
- 燃油箱故障或损坏
- 燃油箱压力传感器、线路或计算机故障
- 碳罐故障
- 滤毒罐排气阀有缺陷 - 在某些情况下
常见误诊
排放的污染气体
- HCs（碳氢化合物）：未燃烧的原燃料液滴，有异味，影响呼吸，导致烟雾。
基础知识
燃油箱压力传感器是一个跟踪燃油存储或蒸发控制（EVAP）系统中任何正压或负压变化的装置。 它不断将压力信息传递给动力总成控制模块（PCM）。 燃油箱压力传感器位于燃油箱顶部或燃油泵和燃油表模块上或附近。
See_also: P2163 OBD II故障代码 面向修理厂和技术人员的P0451诊断理论
当压力传感器的读数不合理和/或在冷起动后车辆运行10秒钟内超出范围时，设置蒸发控制系统压力传感器范围/性能代码。 该代码使用 "两次跳闸 "逻辑，这意味着故障条件必须在连续两次冷起动和车辆运行期间存在。
评估燃油箱压力传感器的常见测试
- 检索代码并写下冻结帧信息，作为测试和验证任何维修的基准。
- 通过扫描工具观察油箱压力的数据流，密切注意油箱压力的读数。 油箱压力传感器是否正常工作？ 如果不正常，系统将认为没有产生真空，而实际上，油箱压力传感器无法读取正在产生的真空。 油箱压力传感器是主要的反馈传感器，它可以将油箱压力传感器的读数转换为系统的读数。动力总成计算机依靠泄漏测试数据。
- 检查并测试燃油压力传感器接线，确认 PCM 有 5 伏参考信号、良好的接地以及到 PCM 的良好信号返回电路。
- 在扫描工具上观察数据流变化（或无数据流变化）的同时，用真空计测试压力传感器，同时将其连接到线束上。
- 如果上述所有测试结果均符合规格，则问题可能出在PCM本身。
Ronald Thomas
Jeremy Cruz is a highly experienced automotive enthusiast and a prolific writer in the field of auto repair and maintenance. With a passion for cars that dates back to his childhood days, Jeremy has devoted his career to sharing his knowledge and expertise with consumers who seek reliable and accurate information about keeping their vehicles running smoothly.As a trusted authority in the automotive industry, Jeremy has worked closely with leading manufacturers, mechanics, and industry experts to gather the most up-to-date and comprehensive knowledge in auto repair and maintenance. His expertise extends to a wide range of topics, including engine diagnostics, routine maintenance, troubleshooting, and performance enhancement.Throughout his writing career, Jeremy has consistently provided consumers with practical tips, step-by-step guides, and trusted advice on all aspects of auto repair and maintenance. His informative and engaging content allows readers to understand complex mechanical concepts easily and empowers them to take control of their vehicle's well-being.Beyond his writing skills, Jeremy's genuine love for automobiles and innate curiosity have driven him to constantly stay abreast of emerging trends, technological advancements, and industry developments. His dedication to informing and educating consumers has been recognized by loyal readers and professionalsalike.When Jeremy isn't immersed in automobiles, he can be found exploring scenic driving routes, attending car shows and industry events, or tinkering with his own collection of classic cars in his garage. His commitment to his craft is fueled by his desire to help consumers make informed decisions about their vehicles and ensure they have a smooth and enjoyable driving experience.As the proud author of the blog for the leading provider of auto repair and maintenance information to consumers, Jeremy Cruz continues to be a reliable source of knowledge and guidance for car enthusiasts and everyday drivers alike, making the road a safer and more accessible place for all.
