help!!! 2009 audi a4 2.0 tfsi b8 oil pressure sensor
 

hi i need help about my 2009 audi a4 2.0 tfsi b8, 3 month ago i was a message said " turn off the engine and check level oil, im was going to mechanic garage et they told me to change level sensor oil and an other sensor near the oil filter. but i dont issue the problem... now they tell me to change oil pressure sensor, but i dont know where it is located... someone knows where it is??? and they tell me if after remplace it, and if the problem is not issue.. i have to change oil pump??? cam someone help me please!!! sorry for my english i speak french or spanish