Auto Lamps And/Or Fog Lights Not Operating Properly
NOTE:
Ensure headlights and fog lights operate properly before performing the following test procedure.
- Turn fog lights off. Turn headlight switch to AUTO position. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Using scan tool, check headlight switch voltage. If approximately 2.3 volts is displayed, go to next step. If approximately 2.3 volts is not displayed, replace headlight switch.
- Turn fog lights on. Using scan tool, check headlight switch voltage. If approximately 3.7 volts is displayed, go to next step. If approximately 3.7 volts is not displayed, replace headlight switch.
- Using scan tool, monitor sun sensor/VTSS indicator voltage. Shine bright light on sun sensor/VTSS indicator, then cover sun sensor/VTSS indicator. Voltage display should change from zero volts to 5 volts. If voltage displayed is always greater than 4.8 volts, go to next step. If voltage is always .5 volt or less, go to step 8 . If voltage is as specified, replace Body Control Module (BCM).
- Turn ignition off. Disconnect sun sensor/VTSS indicator harness connector. Using a fused jumper wire, connector terminals No. 1 (Dark Blue wire) and No. 2 (Dark Blue/Gray wire) at sun sensor/VTSS indicator harness connector. See Fig 1 . Turn ignition on. Using scan tool, check sun sensor/VTSS indicator voltage. If greater than .5 volt is displayed, go to next step. If .5 volt or less is displayed, replace sun sensor/VTSS indicator.
- Turn ignition off. Disconnect BCM harness connector C2. Measure resistance in Dark Blue wire between terminal No. 1 at sun sensor/VTSS indicator harness connector and terminal No. 10 at BCM harness connector C2. See Figure and Fig 1 . If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, repair open in Dark Blue wire between sun sensor/VTSS indicator and BCM.
- Turn ignition on. Measure voltage at terminal No. 10 (Dark Blue wire) at BCM harness connector. If no voltage exists, go to next step. If any voltage exists, repair short to voltage in Dark Blue wire between sun sensor/VTSS indicator and BCM.
- Turn ignition off. Disconnect BCM harness connector C1. Measure resistance in Dark Blue/Gray wire between terminal No. 2 at sun sensor/VTSS indicator harness connector and terminal No. 8 at BCM harness connector C1. If resistance is 5 ohms or less, replace BCM. If resistance is greater than 5 ohms, repair open in Dark Blue/Gray wire between sun sensor/VTSS indicator and BCM.
- Turn ignition off. Disconnect sun sensor/VTSS indicator harness connector. Turn ignition on. Using scan tool, check sun sensor/VTSS indicator voltage. If 4.8 volts or less is displayed, go to next step. If greater than 4.8 volts is displayed, replace sun sensor/VTSS indicator.
- Turn ignition off. Disconnect BCM harness connector C2. Measure resistance between ground and terminal No. 1 (Dark Blue wire) at BCM harness connector C2. See Figure . If resistance is greater than 1000 ohms, replace BCM. If resistance is 1000 ohms or less, repair short to ground in Dark Blue wire between sun sensor/VTSS indicator and BCM.