U.S. Customs and Border Protection (CBP) has issued CSMS #68559236 offering guidance on the application of Section 232 tariffs to the value of the non-US content in Medium and heavy-duty vehicles (MHDVs).
https://content.govdelivery.com/bulletins/gd/USDHSCBP-4162184?wgt_ref=USDHSCBP_WIDGET_2