I have a new My Passport for Mac.
I am using the drive out of the box, so the file system is HFS+J.
Using Disk Utilities the Drive is OK.
Using WD Drive Utilities the SMART diagnostics are OK; it passes the Quick Drive Test.
DiskWarrior reports the file system as OK.
It fails when running the Complete Drive Test. Usually after abou 30% completion.
Answering my own question.
I turned off the screen saver, screen power off, etc. Now the Mac contunues to run with no time limitation.
This fixed the problem. The WD Disk Utilities completed the full disk test OK.
It took about 6 hours.
Maybe WD can fix this problem. Or add a note to the instructions.
Normally, all operations are suspended when a computer system goes to sleep.
Im having this same exact problem and I just got this mac in decmeber and i dont really know how to use it yet. I could really use some help with how to fix it if you could tell me the steps you took it would be appreciated.