CUSTOMER CONCERN The vehicle stalled while driving, required towing, and had a depleted high-voltage battery with DTCs P261A13, C1259, and C1A50. CAUSE The confirmed repair identified a failed 12-volt auxiliary battery as the cause of the stall and related hybrid-system faults. CORRECTION Remove and replace the failed 12-volt auxiliary battery, clear DTCs P261A13, C1259, and C1A50, and verify Ready mode, charging, and normal vehicle operation.