DTC P1706: Park/Neutral Position Switch: Description
WARNING: This page is about a different car, the 2003 Nissan Altima. However, it is still accessible from the selected car via links, so may be relevant.
When the shift lever position is "P" (A/T models only) or "N", park/neutral position (PNP) switch is ON. ECM detects the position because the continuity of the line (ON signal) exists.