故障现象一辆奥迪A6 2.5TDI轿车,累计行驶里程约为6万km,出现发动机熄火后无法起动着机的现象。故障诊断首先连接VAS5052进行故障查询,各控制单元内没有故障代码储存。由于发动机无法起动着机(起动机运转正常),接着进行油路检查。经检查低压系统压力仅为为0.5 bar(1 bar=100 kPa),但更换燃油泵进行排气后,发动机仍旧不能起动着机。根据该款柴油发动机的工作特点分析,认为故障范围有:柴油品质或油路问题;发动机正时或喷油正时有问题;气缸压力有问题;防盗系统或相关线路故障。接着针对上述可能的故障范围进行检查。油路经检查 Symptoms An Audi A6 2.5TDI sedan, the cumulative mileage of about 60,000 km, the engine fails to start the machine after the phenomenon. Fault diagnosis First connect VAS5052 fault inquiry, there is no fault code stored in each control unit. Since the engine can not start the machine (starter running properly), then check the oil. After checking that the pressure in the low-pressure system is only 0.5 bar (1 bar = 100 kPa), the engine still can not start up after exchanging the fuel pump for exhaust. According to the diesel engine operating characteristics of the analysis, that the fault range: diesel quality or oil problems; engine timing or fuel injection timing problems; cylinder pressure problems; anti-theft system or related line failure. Then check for the above possible fault range. Oil inspection