When boot the PCIE fuction,the Xavier module system crash and dead

we had done a new carried board and the carried board can bring up two Xavier module; the Two module connnected by PCIE (PCIE*8 I/F C5);one module(A) is RT ,the ohter(B) is EP. When boot the PCIE,A and B ‘s VIN_PWR_BAD_N had a drop ,this signal of A moudle is 260mV ,but the signal of B moudel is 460mV to 500mV,the B moudel crash;and we remove all the associated connection between the carried board and the Xavier module of this signal(VIN_PWR_BAD_N ),the problem is the same with before.So I want to know why open the PCIE ,the signal of VIN_PWR_BAD_N had drop,and how we can analyse; the input of power is 300W/12V;and the input power no drop;

if we do not use PCIE ,the two module work normal

You mean thare are 2 modules on one carrier board?
This seems to be related with the HW design, not sure if able to have suggetion. will forward to internal team to do investigation.

If there is no other part design issue, please refer to the PCIe design appnote as below. There are some requests on this, like the buffers between RP and EP control signals and etc.

https://developer.nvidia.com/embedded/dlc/jetson-agx-xavier-series-pcie-endpoint-design-guidelines-application-note