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DTC B2419: Ambient Light Sensor Circuit Problem: Testing

  1. If body control system diagnostic check has been performed, go to next step. If body control system diagnostic check has not been performed, perform body control system diagnostic check. See BODY CONTROL SYSTEM DIAGNOSTIC CHECK  under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Connect scan tool to Data Link Connector (DLC). Select OPEN/SHORT DATA from IPM DATA DISPLAY. Set ambient light sensor units to COUNTS. Cover ambient light sensor. If scan tool indicates that ambient light sensor value is greater than 250 counts, go to step  6 . If scan tool does not indicate that ambient light sensor value is greater than 250 counts, go to next step.
  3. Expose ambient light sensor to bright incandescent light. If ambient light sensor value is now less than 5 counts, go to step  9 . If ambient light sensor value is not less than 5 counts, go to next step.
  4. Use scan tool to clear DTCs. Turn ignition switch to OFF position, then to ON position. Recheck for DTCs. If DTC B2419 resets, go to next step. If DTC B2419 does not reset, check for intermittent connection.
  5. Replace IPM. See INSTRUMENT PANEL INTEGRATION MODULE (IPM)  under REMOVAL & INSTALLATION. After replacing IPM, go to step  14 .
  6. Turn ignition switch to OFF position. Disconnect ambient light sensor connector. Cover ambient light sensor. Using DVOM, measure resistance between sensor terminals "A" and "B" (component side). If resistance is greater than 3.1 k/ohms, go to next step. If resistance is less than 3.1 k/ohms, go to step  12 .
  7. Disconnect IPM connector C2. Using DVOM, measure resistance in White wire between IPM connector terminal B5 and ambient light sensor connector terminal "A". See Figure . If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, go to step  13 .
  8. Repair open in Yellow wire between splice and ambient light sensor. After repairs, go to step  14 .
  9. Turn ignition switch to OFF position. Disconnect ambient light sensor connector. Expose ambient light sensor to bright incandescent light. Using DVOM, measure resistance between sensor terminals "A" and "B" (component side). If resistance is greater than 2.3 k/ohms, go to step  12 . If resistance is less than 2.3 k/ohms, go to next step.
  10. Disconnect IPM connector C2. Using DVOM, measure resistance between ground and IPM connector C2 terminal B8 (Yellow wire). If reading is less than 5 ohms, go to next step. If reading is greater than 5 ohms, go to step  5 .
  11. Repair short to ground in Yellow wire. After repairs, go to step  14 .
  12. Replace ambient light sensor. After replacing ambient light sensor, go to step  14 .
  13. Repair open on White wire between IPM and ambient light sensor. After repairs, go to next step.
  14. Reconnect all components and connectors. Turn ignition switch to ON position. Using scan tool, clear DTCs. After clearing DTCs, perform body control system diagnostic check. See BODY CONTROL SYSTEM DIAGNOSTIC CHECK  under SYSTEM TESTS.
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