I apologize if this has already been addressed (I tried a forum search and did not get any hits). It appears that the values for ACCEL_FS_SEL in the ACCEL_CONFIG0 register are given incorrectly in the ICM-42688 Datasheet. The values for 0 through 4 should be 32G down to 2G. The PDF currently states that the maximum range, for a index value of 0, is 16G, when it should be 32G. I have verified this empirically.
I also note that in the Icm426xxDefs.h header file, the maximum value is shown to be 32G for the ICM-42686 chip, so I assume this should also be the case for the ICM-42688 chip.
Thank you,
dale