Crankshaft sensor on 2004 Infiniti G35

Does anyone know where the crankshaft sensor is located? I was told that it was bad and that I had to replace it, I bought the part from the dealer and took to my mech. but we can not locate its position.

2 answers
The image I have shows the crank angle sensor located under the car, just beneath the clutch slave cylinder (so it is at the rear of the engine and underneath).
it is under the driver side of the car on the gearbox