Auto Dimming Comp/Temp Mirror. The mirror's compass and outside temperature displays are features of the PathPoint™ Compass System developed by Johnson Controls, a Johnson Controls Company. The compass is a self-calibrating flux gate compass that eliminates manual calibration by the factory, dealer or customer. It detects and compensates for magnetic anomalies caused by bridges, subways and large steel structures. It also compensates for actual changes in vehicle magnetics. Calibration data is stored in memory, which eliminates any requirement for recalibration after losing battery power. The electronic compass shows the direction you are heading in an easy to read digital display located above the mirror. The compass is an extremely accurate computer that displays vehicle headings of N, NW, W, SW, S, SE, E and NE. The outside temperature display provides you with a digital temperature reading. When the temperature is at or below 37 degrees the display will indicate "ICE" for a period of one minute. This feature cautions you to anticipate road-icing conditions.