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DTC B2473: High Beam Fault: Testing

NOTE: If DTC B2473 is a history code, problem may be intermittent. Wiggle wires while performing the following test.
  1. If BCM system check was performed, go to next step. If BCM system check was not performed, go to BCM DIAGNOSTIC SYSTEM CHECK  under SYSTEM TESTS.
  2. Connect scan tool to DLC. Select HIGH BEAMS from light test menu in SPECIAL FUNCTIONS. While observing scan tool, press on button on scan tool. If status changes and high beam lights operate with commanded state, go to next step. If status does not change or high beam lights do not operate with commanded state, go to step  4 .
  3. While observing scan tool, press off button on scan tool. If status changes and high beam lights turn off with commanded state, go to step  6 . If status does not change or high beam lights do not turn off with commanded state, go to step  7 .
  4. Disconnect BCM 32-pin connector C2. Remove LH and RH headlamp relays. Using DVOM, measure resistance between LH headlamp relay terminal No. 1 and BCM connector C2 terminal C8 (White wire). See WIRING DIAGRAMS  . See Figure . If open circuit is found, go to step  8 . If circuit is okay, go to next step.
  5. Using DVOM, measure voltage between ground and BCM connector C2 terminal C8. If battery voltage is indicated, go to next step. If battery voltage is not indicated, go to step  10 .
  6. Problem is not present. Check for poor connections at BCM connector C2. Check for intermittent open or short to voltage in White wire between BCM, LH and RH relay. After repairs, go to step  12 .
  7. Using DVOM, measure resistance between ground and BCM connector C2 terminal C8 (White wire). If infinite (OL) resistance is indicated, go to step  12 . If any resistance is indicated, go to step  9 .
  8. Repair open in White wire between headlight (high beam) relay and BCM. After repairs, go to step  12 .
  9. Repair short to ground in White wire between RH, LH headlight (high beam) relay and BCM. After repairs, go to step  12 .
  10. Repair short to voltage in White wire between RH, LH headlight (high beam) relay and BCM. After repairs, go to step  12 .
  11. Replace BCM. See BODY CONTROL MODULE (BCM)  under REMOVAL & INSTALLATION. Reprogram BCM. See PROGRAMMING  . After repairs, go to next step.
  12. Use scan tool to clear DTCs. Verify proper headlight operation. Recheck for DTCs. If DTC B2473 is present, go to step  2 . If DTC B2473 is not present, system is okay.
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