IBM 5162 - Documentation Pointers
"An Introduction to the XT Model 286"
Pages 1145-1152 (PDF pages 1177-1184) of Upgrading and Repairing PCs - Tenth Anniversary Edition
IBM manual - 'Technical Reference'
Found at this link
IBM 5162 and 5170 Service Summary
Computerworld magazine article (Nov 1986)
Discusses apparent lack of demand.
Note that the AT (IBM 5170) used as a comparison is the AT of the time, the 8 MHz version of the AT, not the earlier released 6 MHz models.
PC Magazine article (Feb 1987)
Discusses possible connection to the rumoured 'PC II'.
InfoWorld Magazine article (Jul 1987)
Time of introduction to market, and removal from market.