This error could be related to an HBA, required BIOS update, or a hardware fault in the processor component chain.
Prior to calling Dell, I would update the BIOS of the 2850 to A04. If you have an HBA in the box, be sure to update to the latest (supported) firmware. On many occasions, I have seen this error caused by a faulty add-in card. That is a much easier issue to fix IMHO.

If the problem persists, then you will need to swap the processors to determine if a processor, vrm, or other issue is causing your problem. When you swap the processor, you will need to clear the ESM log to confirm that you are not simply looking at the same error. You can clear the ESM log with OpenManage Server Administrator.

Refer to the support Matrix for the PE2850 and confirm your BIOS, BMC, DRAC, and SCSI-RAID firmware and drivers match the matrix.

It may not seem important to update the DRAC firmware to you, but I consider it very important.

If this does not resolve your problem, then take the following journal id, 061013H9FL, to the one-stop troubleshooting website and carry out the next steps required.