LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 1998 >> Seville STS >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Control Module >> Diagnosis & Testing >> DTC B1318: Driver-Side Solar Sensor >> Circuit Description
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit Description

The solar sensor (located on top left of dash) is a light sensitive photodiode that controls signal voltage to Instrument Panel Integration Module (IPM). IPM monitors voltage on circuit No. 590 (Light Blue/Black wire) between IPM and driver-side solar sensor. See WIRING DIAGRAMS  .

When sensor is in direct sunlight, IPM reads a low signal voltage at IPM harness connector terminal B2. 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.