Hi @ykp3036
The LPI2C module in S32K1xx devices cannot support High-Speed mode. Section 52.1.1 (Instantiation information) of the reference manual specifies the features/characteristics/restrictions for LPI2C implemented in these devices.
LPI2C module operates normally at 100kbps (as stated in Hardware design guidelines), however, it can also operate at 400kbps as its maximum baud rate value.
Also, please refer to section 52.3.2.4 (Timing Parameters).