DTC U2153: Navigation Module Internal Failure: Description
WARNING: This page is about a different car, the 2001 Cadillac Seville. However, it is still accessible from the selected car via links, so may be relevant.
VICS circuit board installed in Navigation Module (NAV) and communicates with main circuit board in NAV over a dedicated connection within NAV case. This DTC indicates an internal fault inside NAV case. DTC will store when there is no response from VICS processor when queried by NAV, after successfully initializing system. When DTC is stored, VICS switch disappears from navigation system menu. DTC will clear when NAV receives a response from VICS processor.