Exhaust Gas Temperature (EGT) Sensor. Part Number: 059906088CL. Supersession (s) : 059-906-088-CL; 059906088BJ; 59906088CL. . Exhaust Gas Temperature (EGT) Sensor. A Sensor to measure the Temperature of Exhaust Gases at various points of the Exhaust flow of a vehicle. From 05/27/2013. From 09/09/2013. Location-Before Turbocharger.Audi Q7 (4MB, 4MG) 3.0 TDI quattro 2016 with CRTC engine code, was loosing coolant and was diagnosed by Audi dealership as coolant regulator valve was leakin Step 1: Locate the sensor. The IAT sensor is usually located in the air intake boot, but it may also be located in the air cleaner housing or intake manifold. Step 2: Disconnect the negative battery cable. Disconnect the negative battery cable and set it aside. Step 3: Remove the sensor’s electrical connector. Figure 1 The coolant temperature sensor is located on the lower left side of the cooling system. It is on the lower left hose coming from the radiator (red arrow). The coolant fluid will drain out when you remove it so be prepared to either catch the coolant and reuse it or properly dispose of it.
The CTS is new, genuine from Audi and also the symptom only happens with A/C is OFF while driving. However, if car is parked after highway driving than it obviously doesn't matter since A/C will be off hence the suspicion of the aux pump. Although I don't really know if the aux coolant pump is an after-run pump like the turbos or not.