ELECTRICAL ISOLATION DETECTION WITH ENHANCED DYNAMIC RANGE

A bus terminal (21) is isolated from ground potential during normal operation of the vehicle. A first current is applied to the bus terminal (21). A current level detector (50) is arranged to detect a first level of the first current, or a corresponding observed voltage level, that exists or flows from the bus terminal (21) to ground. A compensator (79) is configured to compensate for a range in the detected first level by applying a corresponding compensating voltage level to a first resistor (e.g., in resistive network 75) coupled to the current level detector (50). An electronic data processor (62) is capable of estimating a first isolation level between the bus terminal (21) and ground (99) based on the detected first level.