Hello Paul Emery,
S70GL02GS is not listed in the flash programmer device list in the latest CodeWarrior 10.5.1.
You could refer to the application note in C:\Freescale\CW_PA_v10.5.1\PA\PA_Tools\FlashToolKit\Documentation\AppNote-FlashProgrammer-PowerArchitecture.pdf to add new flash programming algorithm and device in CodeWarrior.
You could refer to the sample flash programming algorithm projects in C:\Freescale\CW_PA_v10.5.1\PA\PA_Tools\FlashToolKit.
Thanks,
Yiping