The following Pioneer radio models will not work with a connected bypass.
They require internal bypassing. Pioneer changed some things in these radios.
DMH-2700NEX, DMH-W4400NEX, DNH-W4500NEX, DMH-W4600NEX, DMH-W4660NEX, DMH-W6500NEX, DMH-W6600NEX, DMH-W7600NEX , DMH-W7660NEX, DMH-W8660NEX, DMH-WC5700NEX, DMH-WC6600NEX, DMH-WT5700NEX, DMH-WT6000NEX, DMH-WT7600NEX,DMH-WT8600NEX, DMH-WT8900NEX.