macOS (10.14): Disables AHT, Apple Diagnostics on Select Macs

Created on: July 29, 2019
Last updated: April 9, 2020

Current as of April, 2020

Affected Macs (confirmed):

  • MacBookAir5,1

  • Macmini6,2

  • MacBookPro9,1

  • MacBookPro9,2

  • MacBookPro10,1

May also be impacted:

  • MacBookAir5,2
  • Macmini6,1
  • MacBookPro10,2

Please be aware that if you own any of the model IDs listed above — whether purchased from OWC or other sources — and you install macOS 10.14 or later on your Mac, it will disable future use of the Apple Hardware Test and Apple Diagnostics test. If you attempt to run either test afterward, you will receive this error: 

Error: 0x8000000000000003, Cannot Load 'EFI/Drivers/TestSupport.efi'

Status: 0x00000003

Note that receiving this error does not mean your Mac is defective or non-functional. It simply means the OS you have installed has removed certain resources which are required to run these tests successfully. Please know that for OWC-purchased hardware we run an extensive set of tests on all New and Used Macs before making them available on, ensuring everything works well before the product reaches you.

It is also important to note the list above may not be exhaustive; it is possible other 2012 (and earlier) Mac models are affected. OWC will continue to add models to the list as we confirm them, based on test results.

If your computer is working normally but you happen to notice it does not pass an Apple Diagnostic or Apple Hardware Test, please do not be alarmed. This is expected. In general, if your MacSales-purchased Mac computer does not boot or exhibits performance problems during use, you can always contact our award-winning support team to get you back on track.