Hello Bilal,
could you please follow the procedure below:
1. Download OpenSDA Firmware (MSD & Debug) at link http://www.pemicro.com/opensda
Firmware Apps (.zip file).
Latest MSD & Debug applications. Updated June 28th, 2017.
2. You can find the update steps in file OpenSDA Firmware Update Instructions.pdf file.
3. Extract the DEBUG-OPENSDA-E200_Pemicro_v110.SDA file from the zip file.
4. Keep pressing the button SW3 (not SW1) , and connect the DEVKIT-MPC5748G to the your PC using OPENSDA by USB cable.
5. You'll find a new BOOTLOADER driver on your PC, then copy the SDA file to the driver .
6. reset the DEVKIT-MPC5748G .
There is whole topic, which discuss this issue:
Failed to debug MPC5748G at 98% for S32DS v1.2
Please let me know, if the procedure help you.
Regards
Martin