Who was the disc purchased through? New or used? And what is the part number on it. It may be the case that there was a problem with the unit prior to purchase, which could explain no map disc. Here is one of many bulletins that may apply. The possibilities on nav radio concerns are many, and the radios are spendy. First is to verify that the disc is correct for the vehicle, and that it is in good shape. Here is that bulletin.
#05-08-44-012: Navigation Radio Inoperative or Does Not Recognize that a Map DVD is Inserted (Replace Navigation Radio) - (Apr 20, 2005)
Subject: Navigation Radio Inoperative or Does Not Recognize That a Map DVD is Inserted (Replace Navigation Radio)
Models: 2004-2005 Cadillac DeVille, XLR
2005 Cadillac SRX
with Navigation Radio (RPO U3R (DeVille), U2V (SRX), U2R (XLR))
Some customers may comment on an inoperative navigation radio or that the navigation radio does not recognize a map DVD when it is inserted into the radio.
This condition may be caused by a problem with the thread motor inside the radio. The thread motor moves the arm that holds the laser in order to read the information from the map DVD.
Verify that the only customer concern is that the navigation radio does not recognize that the map DVD has been inserted into the radio. If the customer concern is anything other than this, refer to the Diagnostic Starting Point-Entertainment procedure in SI to begin your diagnosis.
If the only customer concern is that the map DVD is not recognized, then technicians are to use the following procedure to resolve this customer concern:
Eject the navigation map DVD that is currently in the radio.
Visually inspect the DVD for scratches or other damage.
Reinsert the map DVD and press "I Agree".
If no map information is displayed, eject the navigation map DVDs and insert a known good map DVD. If the radio now displays map information, the customer's original map DVD is defective.
Important: Remember to remove any DVDs that are in the radio before it is sent out for repair.
If map information is still not displayed, replace the navigation radio. Refer to the Radio Replacement procedure in SI for more information (Document IDs 792964 (DeVille), 702067 (SRX), 1212196 (XLR)).
Monday, January 18th, 2010 AT 9:54 PM