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DTC B2472: Low Beam Fault: Testing

  1. Perform lighting system diagnostic system check. See LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check, go to next step.
  2. Turn ignition off. Connect scan tool to DLC. Turn ignition on. Select LOW BEAM from light test menu in SPECIAL FUNCTIONS on scan tool. While observing low beam headlights, press on and off buttons on scan tool several times. If low beam headlights operate with commanded state, go to DIAGNOSTIC AIDS  . If low beam headlights do not operate with commanded state, go to next step.
  3. Turn headlight switch to OFF position. Remove low beam relay from relay box. See Figure . Using a test light connected to ground, probe Yellow wire at low beam relay terminal No. 4. If test light illuminates, go to next step. If test light does not illuminate, go to step  11 .
  4. Connect test light between low beam relay terminals No. 1 (Brown/Red wire) and No. 4 (Yellow wire). Using scan tool, command low beam relay on and off. If test light turns on and off when low beam relay is turned on and off by scan tool, go to step  8 . If test light does not turn on and off when low beam relay is turned on and off by scan tool, go to next step.
  5. If test light remains illuminated each time low beam relay is turned on and off by scan tool in above step, go to step  10 . If test light does not remain illuminated each time low beam relay is turned on and off by scan tool in above step, go to next step.
  6. Using DVOM, test Brown/Red wire between BCM 32-pin connector C2 terminal C9 and low beam relay terminal No. 1 for an open or high resistance. If fault is located and repaired, go to step  15 . If fault is not located and repaired, go to next step.
  7. Using DVOM, test Brown/Red wire between BCM 32-pin connector C2 terminal C9 and low beam relay terminal No. 1 for an open or high resistance. Also test Brown/Red wire between headlight switch connector terminal No. 4 and low beam relay terminal No. 1. See HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article. If fault is located and repaired, go to step  15 . If fault is not located and repaired, go to step  9 .
  8. Inspect for poor connections at low beam relay harness connector. If fault is located and repaired, go to step  15 . If fault is not located and repaired, go to step  13 .
  9. Inspect for poor connections at BCM 32-pin connector C2. If fault is located and repaired, go to step  15 . If fault is not located and repaired, go to step  14 .
  10. Using DVOM, test Brown/Red wire between BCM 32-pin connector C2 terminal C9 and low beam relay terminal No. 1 for short to ground. Also test Brown/Red wire between headlight switch connector terminal No. 4 and low beam relay terminal No. 1 for short to ground. If fault is located and repaired, go to step  15 . If fault is not located and repaired, go to step  12 .
  11. Locate and repair open in Yellow wire between low beam relay terminal No. 4 and fuse block. After repair, go to step  15 .
  12. Replace headlight switch. After repair, go to step  15 .
  13. Replace low beam relay. See REMOVAL & INSTALLATION  . After repair, go to step  15 .
  14. Replace BCM. See BODY CONTROL MODULE (BCM)  under REMOVAL & INSTALLATION. Reprogram BCM. See PROGRAMMING  . After repair, go to next step.
  15. Use scan tool to clear DTCs. Recheck for DTCs. If DTC B2472 is present, go to step  2 . If DTC B2472 is not present, system is okay.
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