Hi Minggang,
Desaturation error:
If the high-side power FET is turned on and the drain source voltage VDS is greater than Vdesaths after the blanking time tBLANK a desaturation error will be flagged. In this case, the associated desaturation error flag GDHSIF[2:0] will be set and the high-side power FET will be turned off. The level of the voltage Vdesaths can be adjusted in the range of 0.35 to 1.40V in GDUDSLVL register.
I suppose, that issue will be probably in some incorrect settings or hardware connection.
Could you share with us your schematic for short review?
I suppose, that you use one of reference projects as a template.
http://www.nxp.com/products/software-and-tools/run-time-software/automotive-software-and-tools/motor...
Could you please share with us your project or at least your settings for short review?
If any of this information are not public, you may create service ticket:
https://community.nxp.com/docs/DOC-329745
I hope it helps you.
Have a great day,
Radek
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------