I am looking if MC9S12ZVCAx has a unique ID or a serial number and what function I need to call to obtain the said ID?
The document related to your question exists on the community see below link:
How to get device ID and write program once field without programming application to the S12Z device...
In the reference manual of S12ZVC, you can find the address where version ID is stored see 20.4.2 IFR Version ID Word and Table 20-5. Program IFR Fields
I hope it helps you.