Hmmm.... Work Shop Codes (WSC) are a feature of every module and they are not particularly special to the diagnostic device. So, WSCs can (and generally they) different for each module.
The best way to demonstrate this is through a scan report. Unfortunately one of the (many) deficiencies in OBD11 scan reports is that they don't show the WSC - but VCDS does a much better job of this.
Here's a extract of a VCDS auto-scan report from my Audi:
-------------------------------------------------------------------------------
Address 01: Engine (J623-CZEA) Labels:. 04E-907-309-V1.clb
Part No SW: 04E 906 027 HF HW: 04E 907 309 BJ
Component: R4 1.4l TFS H24 3744
Revision: R6H24---
Coding: 02250032236401083000
Shop #: WSC 06314 790 00021 ASAM Dataset: EV_ECM14TFS01104E906027HF 001007
ROD: EV_ECM14TFS01104E906027HF.rod
VCID: 6FAE16D4B6DCA43CCD-803A
CAN Converter 01:
No fault code found.
Readiness: 0000 0000
-------------------------------------------------------------------------------
Address 02: Auto Trans (J743) Labels: 0CW-927-769.clb
Part No SW: 0CW 300 041 Q HW: 0AM 927 769 E
Component: GSG DQ200G2_M H05 1603
Revision: 00005008 Serial number: CU501712236712
Coding: 0014
Shop #: WSC 17734 418 534600 ASAM Dataset: EV_TCMDQ200021 001001
ROD: EV_TCMDQ200021_VW27.rod
VCID: 43C68A64CAD4705C79-8016
No fault code found.
-------------------------------------------------------------------------------
Address 03: ABS Brakes (J104) Labels:. 5Q0-907-379-IPB-V1.clb
Part No SW: 5Q0 614 517 CH HW: 5Q0 614 517 AH
Component: ESC H62 0743
Revision: 00000000 Serial number: 63357000000216
Coding: 12F18AA2242822708B800A00A0CA2948512444D1500594731821503482A8420000000012121212B835351919323200
Shop #: WSC 06314 790 00021 ASAM Dataset: EV_Brake1UDSContiMK100IPB 036010
ROD: EV_Brake1UDSContiMK100IPB_036_AU37.rod
VCID: 79BA288CF898FA8C63-802C
No fault code found.
-------------------------------------------------------------------------------
Address 05: Acc/Start Auth. (J518) Labels:| 5Q0-959-435.clb
Part No SW: 5Q0 959 435 C HW: 5Q0 959 435
Component: VWKESSYMQB 021 0803
Revision: 00021000 Serial number: 0465996031
Coding: 030C0C
Shop #: WSC 00000 000 00000 ASAM Dataset: EV_KessyHellaMQBAB 002020
ROD: EV_KessyHellaMQBAB_002.rod
VCID: 3C34F198B72A0FA438-8068
No fault code found.
-------------------------------------------------------------------------------
Notice the following in the VCDS scan report:
- each module caries its own WSC (called "Shop" in the VCDS scans).
- for a particular car, the WSCs can be different for different modules - but also, the same WSC can be repeated on multiple modules
- the WSC in the last module (hex05) has a zero-string - this generally means that the module's coding hasn't been altered after manufacture
So this is how I believe that OBD11 handles WSCs:
- Every change to a module's coding must be accompanied by a WSC
- When an OBD11 user presses the "go" button to make a change (either manually, or via an APP), OBD11 looks at the WSC that's already registered for the module
- If the module has a non-zero WSC, OBD11 will use that number for the coding change
- If the module has a zero-string WSC, OBD11 will attempt to use 12345..... as the WSC
Happy to be advised where I have erred!!
Don