WARNING: This page is about a different car, the 2006 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.
Inspect the thickness of the pad through the cylinder body inspection hole. Use a scale for inspection if necessary.
Standard pad thickness: 10 mm (0.394 in)
Pad wear limit: 2.0 mm (0.079 in)
Fig 1: Inspecting Thickness Of Pad Through Cylinder Body