Circuit Description
WARNING: This page is about a different car, the 1998 Cadillac Seville. However, it is still accessible from the selected car via links, so may be relevant.
The passenger-side solar sensor (located on top right of dash) is a light sensitive photodiode that controls signal voltage to the Instrument Panel Integration Module (IPM). IPM monitors voltage on circuit No. 1548 (Gray wire) between IPM and passenger-side solar sensor. See WIRING DIAGRAMS .
When sensor is in direct sunlight, IPM reads a low signal voltage at IPM harness connector terminal B3. When sensor is shaded, signal voltage increases. Signal voltage varies from 5 volts (open circuit) to zero volts (short circuit). DTC will set when ignition is on and or when sensor circuit is open or shorted.