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).
Use chips with an access time rating of 170 ns, or faster. (source)
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.
Modified 04/21/86 BIOS
There is a modified 04/21/86 BIOS available in the VCFF thread at here.
Details of what was changed are in the thread.