if it is ordered as part of the internal part of the Thinkpad, then it shares the same warranty as the rest of the system.
The only thing that doesn't have the same warranty (unless your system is only warranted for 1 year) is the battery, where it only has a 1 year warranty (unless you have specially bought extended warranty for the battery).
Regards,
Jin Li
May this year, be the year of 'DO'!