What tells the transmission when to change gear? sensor or throttle position and where are these sensors located (roughly)?

When she is cold she runs like a dream but once warmed up she tends to run in much higher revs (4500 - 5500) before changing. almost as if it thinks it is in sport mode. Gear changing is smooth if and when it eventually happens.

Vag com test done, faults found and cleared as below:
1) Intake airflow sensor (the one just after the air filter).
2) Enjin temperature control sensor.

Gear oil changed as well
Als no warning lights are coming up on the dash

Dealers tells me to unplug the airflow sensor while car is running and if nothing happens it is not not the sensor ???? He must be confused. He also told me that it could be lots of things. I tried looking for the 'lots of things' but am not exactly sure what it looks like (lol).

If someone can only anser the first question at least so I have a starting point and work my way through.

your help will be greatly appreciated

 

Replaced the airflow sensor and diagnostic brought back no errors. I wonder if it could have somthing to do with the oil pressure in the gearbox?