Symptom: a 03 golf car equipped with 01M automatic transmission, mileage of 50000km, cold normal, hot car upshift delay, when the engine speed rose to 2800r / min, barely rose to 2 block; rose to 3600r / Min, before the upgrade into the 3 block.
    Troubleshooting: the routine inspection, the result is normal oil pressure, transmission oil no smell, oil transparent pure and no impurities, oil level in line with the standard, automatic transmission control unit without fault code. But with VAG1552 view automatic transmission dynamic data flow, the transmission oil temperature rose too fast, combined with the car after the car did not delay the phenomenon of upshift failure, as follows:
    1. Will the oil temperature sensor signal shift, to the control unit a false impression? Then we measured the oil temperature sensor, in each specific temperature range, the measured value and maintenance manual to provide the value of consistent, indicating that the assumption is not true. With the infrared thermometer to monitor the transmission radiator temperature, after a period of time after the transmission oil temperature rose sharply to 120 ℃, the failure followed again, indicating that the fault is caused by high temperature.
    2. If the fault is caused by the high temperature of the transmission, what is the cause of the high temperature of the transmission? Possible reasons are: clutch, brake slip; bad lubrication inside the box; torque converter lock can not lock the clutch; radiator bad heat and so on.
    Because the car in the rise and fall during the period did not appear to run empty and the engine speed steep rise and the speed of the phenomenon is not normal, you can rule out the clutch brake slip. If the box is poor lubrication, it will cause the planetary gear mechanism and bearing copper sleeve wear, serious will make the sun wheel bald teeth, but the car did not find these symptoms, it can also rule out the bad lubrication. If the torque converter lock can not be locked, it will lead to oil temperature rise, the test TCC lock the work of normal performance, observe the torque converter completely locked for a long time after the oil temperature remained at 120 ℃, and Do not drop, should be excluded from the torque converter work. If the radiator heat dissipation, will directly lead to high temperature transmission. To further confirm that the use of infrared thermometer measurement of the radiator inlet and outlet temperature and found that the temperature difference between imports and exports is very small, then the problem is the cooling of the radiator.
    Will remove the radiator, with a wind gun to clear, blowing a lot of yellow muddy sediments, with cleaning agent after repeated cleaning and recovery, after up to 2h of the test, the transmission oil temperature is always maintained at 96 ~ 97 ℃ or so, The time back to normal, troubleshooting.
    Maintenance Summary: owners in more than a year ago to add a different brand of antifreeze, so that the cooling system suffered corrosion and produced a large number of ion particles, resulting in the radiator blockage.