Test 48B - Auto Headlight Sun Sensor Input Circuit
NOTE:
Perform TEST 47A
before proceeding with this test. For connector terminal ID, see CONNECTOR IDENTIFICATION
. For wiring schematics, see WIRING DIAGRAMS
in this article. Perform TEST VER-1 - VERIFICATION PROCEDURE
after each repair.
CAUTION:
Always turn ignition off prior to disconnecting any module connector.
- Cover sun sensor. Sun sensor is located at center of upper dash. Using scan tool, read auto headlight sensor voltage. If scan tool displays more than 4.8 volts, go to step 4). If scan tool displays 4.8 volts or less, go to next step.
- Disconnect sun sensor connector. For dash removal and installation procedure, see INSTRUMENT PANEL article in the ACCESSORIES & ELECTRICAL section. Using scan tool, read auto headlight sensor voltage. If scan tool displays AUTO HEADLIGHT SENSOR: 5.0V, replace sun sensor. If scan tool does not display AUTO HEADLIGHT SENSOR: 5.0V, go to next step.
- Turn ignition off. Disconnect Body Control Module (BCM) Gray connector. BCM is located behind right kick panel. Using scan tool in ohmmeter mode, measure resistance at terminal No. 20 (Dark Blue/Red wire) on BCM Gray connector. If resistance is less than 5 ohms, repair short to ground in Dark Blue/Red wire. If resistance is 5 ohms or greater, replace BCM.
- Using scan tool in monitors mode, read ENGINE INFO. If scan tool displays NR (no response), go to TEST 114A . If scan tool does not display NR, observe scan tool while starting engine. If engine speed increases to more than 450 RPM when starting engine, replace BCM. If engine speed does not increase, replace Powertrain Control Module (PCM).