Haynes manual misleading on TPS

2005 grand marquis. This is my first time ever posting on an auto forum. I usually can find what I need. But the Haynes manual for my 2005 Grand Marquis GS 4.6 says the throttle position sensor is supposed to have 3 wires. Mine has 4. I'm a DIY mechanic and learn as stuff breaks, so some areas I'm new to. Any help figuring this out is greatly appreciated.

Rockauto.com shows 4 wire TPS & connector. Sounds like just an error in Haynes.