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DTC B1973: High Power Control Fault: Testing

  1. Perform BCM diagnostic system check. See BODY CONTROL MODULE (BCM) DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
  2. Disconnect BCM 32-pin connector C2. Disconnect multifunction relay module. See Figure . Using DVOM, check voltage at BCM connector C2 terminal D1 (Brown/Blue wire). See Figure . Turn ignition switch to ON position. Check voltage reading. If voltage reading is less than one volt, go to next step. If voltage reading is not less than one volt, go to step  4 .
  3. Fault is not current at this time. Check for short to voltage in Brown/Blue wire between BCM connector C2 terminal D1 and multifunction relay harness connector terminal No. 11. Repair wire as necessary. See WIRING DIAGRAMS  . Reinstall all disconnected components and connectors. Using scan tool, clear DTCs. Check for DTCs. If DTC B1973 is set, go to step  5 . If DTC B1973 is not set, system is okay. No further testing is required.
  4. Repair short to battery voltage in Brown/Blue wire between multifunction relay module and BCM. After repair, go to step  6 .
  5. Replace BCM. See BODY CONTROL MODULE (BCM)  under REMOVAL & INSTALLATION. Reprogram BCM. See PROGRAMMING  . After replacement, go to next step.
  6. Reconnect all disconnected components and connectors. Using scan tool, clear BCM DTCs. Verify BCM operation by turning on headlights, interior lights and cycling ignition locks. If BCM operates properly and DTC B1973 does not reset, system is okay.
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