Conditions for Setting the DTC
WARNING: This page is about a different car, the 2011 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
B2476 04
The CIM detects an open/high resistance on the keypad supply voltage circuit.
B2482 and B2476 59
The CIM detects a valid signal on the keypad signal circuit for longer than 15 seconds. If one of the OnStar® buttons is held or stuck for 15 seconds or greater, the CIM will set this DTC.