This is quick guide on what parts are needed to upgrade a 2009-2017 FX35, FX37, FX50 or QX70 to a 2010-2017 Navigation System. At most, only four NAV parts are required for the conversion:
(1) Touch Screen Display (2) Control Panel for Display (3) Faceplate / Climate Panel (4) NAV Unit / Radio Receiver
PARTS FOR THE CONVERSION
(1) Touch Screen Display
From a 2010-17 FX35, FX37, FX50, QX70, M37, M56, QX56, QX60 or QX80 with Nav.
Part No: 28091-1JA0B, 28091-1JA0D, 28091-1JA0E, 28091-1JA3A, or 28091-1JA3C.
(2) Control Panel for Display (not needed for ‘09 NAV vehicles looking to upgrade)
From a 2009-17 FX35, FX37, FX50, or QX70 with Nav.
Part No: 28395-1CA2A, 28395-1CA2D, or 28395-1CA4D.
(3) Faceplate / Climate Panel (optional for ’09 NAV vehicles, the existing faceplate can be reused)
From a 2010-17 FX35, FX37, FX50, or QX70 with Nav.
Part No: 25391-1BU6A.
or
From a 2009 FX35 or FX50 with Nav. (These faceplates have a hard drive slot on them)
Part No: 5025391-1CA5A or 5025391-1CA5B
(4.a) NAV Unit / Radio Receiver: To convert 2009 - 2017 NON-Nav vehicles
From a 2010-15 G37, Q40, or Q60.
Part No: 25915-1JA0B, 25915-1JA1E, 25915-1JA2B, 25915-3LZ1A, or 25915-3LZ1C
(Note – these nav units don’t natively support RCA inputs; USB input only).
or
The nav units below can also be used, however they may require dealer reprogramming to activate the rear camera, since the 2009+ NAV vehicles have around-view monitoring.
(4.b) NAV Unit / Radio Receiver: To convert 2009 NAV vehicles
From a 2011-17 FX35, FX37, FX50 or QX70.
Part No: 25915-9GE1A, 25915-9GE1B, 25915-9GE1C, 25915-9GE1D, 25915-9GE2A, 259153WY0C, 25915-3WY0D, 259153WY0E, or 25915-3WY2B.
(Note – these nav units don’t typically support RCA inputs; USB input only).
or
From a 2010 FX35, FX50, or EX35.
Part No: 25915-ZX74A or 25915-JJ52C
(Note – these nav units support both RCA + USB inputs).
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With the correct parts all you need is to either purchase a Harness Adapter Kit such as this one: https://www.ebay.com/itm/334124253577
Or Get a Factory Harness From a 2010-17 NAV Vehicle, and then pin-out, cut, & splice the connectors to your existing harness, using the FSM wiring diagrams as a reference. In some cases, additional wiring (like for the microphone) would also need to be fabricated.
And that's all there is to it. Everything can then be installed like it came from the factory. Get the parts you need, adapt the wiring and away you go! Updated Nav, Bluetooth, Display, etc.
Hope that helps.