On the 5162 motherboard, there are two BIOS ROM chips, one in socket U34 and the other in socket U35.
They are two 8-bit chips which, in combination, supply 16 bits to the IBM 5162's 16-bit data bus. Of the pair, U34 is the EVEN/LOW chip and U35 is the ODD/HIGH chip. Diagram here.
There was only one revision of the BIOS, identified by the date of 04/21/86 (there is no version number).
The date format used is MM/DD/YY.
Part numbers, where BIOS supplied in masked ROM form
Click here for content images (can be used to create replacements).
Known problem - POST error of 601
The IBM 5162's motherboard BIOS is very close that of the 1986 dated IBM 5170's, and shares the situation where the POST can sometimes produce a 601 error if the IBM Fixed Disk and Diskette Drive Adapter is substituted. More information on that is in the 'Known problem - POST error of 601' section at here.