transmission oil temp gauge sensor installation for vw vanogan

• 2022-11-29

How: Remove the gearbox. The transmission oil temperature sensor is installed on the valve plate in the transmission oil pan to detect the temperature of automatic transmission hydraulic oil. To replace the oil temperature sensor, it is necessary to drain the oil from the transmission first, then remove the plastic shell in front of the transmission, and then remove the valve plate of the transmission. Be careful not to drag the harness on the valve plate. Finally, the oil temperature sensor of the transmission can be seen under the back of the valve plate, and can be replaced.

The interior of the automobile oil temperature sensor is a negative temperature coefficient semiconductor thermistor. The higher the temperature, the lower the resistance. Refer to the characteristics of negative temperature coefficient thermistor in coolant temperature sensor for the characteristic curve of its resistance changing with temperature. The computer measures the temperature of the hydraulic fluid of the automatic transmission according to the change of its resistance. When the transmission oil temperature is higher than 150 ℃, the torque converter will enter the locking condition immediately. If the transmission oil temperature does not drop after 30s, the torque converter will release the locking condition and the transmission will exit the overdrive. If the oil temperature sensor itself or the harness is short circuited, it will show that the transmission oil temperature is higher than 150 ℃. Therefore, if the oil temperature sensor itself or the harness is short circuited, the torque converter will not enter the locking condition, and the transmission will not have an overdrive gear, and the car will not have a high speed.

Detection method of oil temperature sensor:

(1) Measure the resistance value of the oil temperature sensor:
Remove the transmission oil temperature sensor, place the sensor in a beaker containing water, heat the water in the beaker, and measure the resistance between the two terminals of the sensor at different temperatures.

(2) Standard value of sensor resistance:
Compare the measured resistance with the specified value. If the difference between the measured resistance and the specified value is large, replace it.