To start Apple Diagnostics:
- Turn off your computer if it is on by choosing Shut Down from the Apple () menu.
- Press the power button to turn on your computer.
- Immediately press and hold the D key until Apple Diagnostics begins.
Straight from Apples official documentation. Why won't it work?
MacBook Pro (Retina, 15-inch, Late 2013) 2.6 GHz Intel Core i7 8 GB 1600 MHz DDR3
OS 10.10.4 (14E46) Yosemite.
MacBook Pro (Retina, 15-inch, Late 2013), OS X Yosemite (10.10.4), 2.6GHz IntelCorei7; 8GB1600MHzDDR3;