自动变速箱故障现象：自动变速器出现升档缓慢，发动机转速达4000r/min才能升档，升档时冲击大的现象。

Automatic transmission malfunction phenomenon: The automatic transmission experiences slow upshifting, with the engine speed reaching 4000r/min before upshifting, resulting in significant impact during upshifting.

自动变速箱故障分析：技师检查自动变速器油(ATF)，发现油量正常，无异味。根据现象判断，是发动机动力不足造成自动变速器不易升档。用VAG1552故障阅读仪检测发动机电控系统，调到故障码00561，含义为混合气调整超过极限。将故障码清除后，重新起动发动机，调得的故障码依旧。可能引起此故障码的原因有：一是燃油压力低;二是空气流量传感器信号数值有误;三是炭罐电磁阀卡死;四是排气系统泄漏;五是喷油器堵塞。经检查，燃油压力正常，进、排气系统无漏气现象。做完发动机免拆清洗和节气门体清洗后，清除故障码，再次起动发动机，未调到故障码。读取数据流，各项数据正常。然后进行路试，故障现象仍然存在，没有好转迹象。

Automatic transmission fault analysis: The technician checked the automatic transmission fluid (ATF) and found that the oil level was normal without any odor. Based on the phenomenon, it is determined that insufficient engine power is causing the automatic transmission to be difficult to upshift. Use the VAG1552 fault reading device to check the engine electronic control system and set it to fault code 00561, which means that the mixture adjustment exceeds the limit. After clearing the fault code and restarting the engine, the obtained fault code remains the same. The possible causes of this fault code are: firstly, low fuel pressure; Secondly, there is an error in the signal value of the air flow sensor; Thirdly, the carbon canister solenoid valve is stuck; Fourthly, there is a leakage in the exhaust system; The fifth issue is fuel injector blockage. After inspection, the fuel pressure is normal and there is no leakage in the intake and exhaust systems. After completing the engine non disassembly cleaning and throttle body cleaning, clear the fault code and restart the engine, but do not adjust to the fault code. Read data stream, all data is normal. Then a road test was conducted, and the fault still existed without any signs of improvement.

自动变速箱维修过程：技师用VAG1552故障阅读仪进入自动变速器系统进行故障查询，未发现故障码。随后进行路试，读取自动变速器控制系统的数据流，发现自动变速器在每个档位都能正常工作，只是换档点太迟，换档冲击大。当检查ATF温度时，故障阅读仪显示该温度在153℃-165℃间波动，明显高于正常值。

Automatic transmission maintenance process: The technician used the VAG1552 fault reader to enter the automatic transmission system for fault inquiry, but no fault codes were found. Subsequently, a road test was conducted to read the data stream of the automatic transmission control system, and it was found that the automatic transmission could work normally in every gear, but the shift point was too late and the shift shock was significant. When checking the ATF temperature, the fault reading instrument shows that the temperature fluctuates between 153 ℃ and 165 ℃, significantly higher than the normal value.

该车选用的自动变速器型号为01N，当ATF温度高于148℃时，自动变速器会自动切换至下一个低档位，以加大自动变速油的流动，降低油温，避免自动变速器因过热而损坏。而ATF温度过高时，自动变速器电控单元并不记忆故障码，只有通过读取数据流才能发现。

The automatic transmission model used in this car is 01N. When the ATF temperature exceeds 148 ℃, the automatic transmission will automatically shift to the next lower gear to increase the flow of automatic transmission oil, lower the oil temperature, and avoid damage to the automatic transmission due to overheating. When the ATF temperature is too high, the automatic transmission electronic control unit does not remember the fault code and can only detect it by reading the data stream.

将该车用举升机升起，检查自动变速器油底壳，感觉其温度并没有像故障阅读仪显示的那么高。将发动机熄火静置2h后，再次用VAG1552故障阅读仪检测ATF温度，发现还是160℃，而此时ATF的实际温度只有40℃左右。怀疑ATF温度传感器出现故障。将自动变速器油底壳拆下，拆下自动变速器扁平线束，用万用表测量ATF温度传感器的电阻，检查其阻值是否随温度变化而正常变化。经检测，ATF温度传感器正常(20℃时，其电阻值约为0.25MΩ;60℃时，约为49kΩ;120℃时，约为7.5kΩ)。当用万用表直接从扁平线束的连接器相应端子处检测ATF温度传感器电阻时，发现该数值始终不随温度变化而变化，而是固定在2kΩ不变。据此判断扁平线束损坏。

Raise the car with a lift and check the automatic transmission oil pan. It feels that the temperature is not as high as displayed on the fault reading instrument. After turning off the engine and letting it stand for 2 hours, the VAG1552 fault reading instrument was used again to check the ATF temperature, and it was found that it was still 160 ℃, while the actual ATF temperature at this time was only about 40 ℃. Suspect that the ATF temperature sensor is malfunctioning. Remove the oil pan of the automatic transmission, remove the flat wire harness of the automatic transmission, measure the resistance of the ATF temperature sensor with a multimeter, and check if its resistance changes normally with temperature. After testing, the ATF temperature sensor is normal (at 20 ℃, its resistance value is about 0.25M Ω; at 60 ℃, it is about 49k Ω; at 120 ℃, it is about 7.5k Ω). When using a multimeter to directly detect the resistance of the ATF temperature sensor from the corresponding terminal of the flat wire harness connector, it was found that the value did not change with temperature, but remained fixed at 2k Ω. Based on this, it is determined that the flat wire harness is damaged.