WARNING: This page is about a different car, the 2008 Infiniti FX45 and 2008 Infiniti FX35. However, it is still accessible from the selected car via links, so may be relevant.
Using a circuit tester, check resistance between the headlamp aiming switch connector terminals in each operation status of the aiming switch.
Fig 1: Identifying Resistance Between Headlamp Aiming Switch Connector Terminals