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BCM Diagnostic System Check: Testing

  1. Turn ignition off. Connect scan tool to DLC. Turn ignition on. Using scan tool, attempt to establish communication with BCM. If scan tool communicates with BCM, go to step  15 . If scan tool does not communicate with BCM, go to next step.
  2. Using scan tool, attempt to establish communication with Powertrain Control Module (PCM), Instrument Panel Cluster (IPC) and Electronic Brake Traction Control Module (EBTCM). If scan tool communicates with other systems, go to next step. If scan tool does not communicate with other systems, go to step  9 .
  3. Check BCM-PWR fuse (10-amp), located in instrument panel fuse block. If fuse is blown, go to next step. If fuse is not blown, go to step  5 .
  4. Replace BCM-PWR fuse. Turn ignition off, then on. Check BCM-PWR fuse again. If fuse is blown, go to step  10 . If fuse is not blown, go to next step.
  5. Turn ignition off. Disconnect BCM Natural 10-pin connector C3. Connect test light between ground and BCM harness connector C3 terminal "B" (Orange wire). See WIRING DIAGRAMS  . See Figure . If test light comes on, go to next step. If test light does not come on, go to step  11 .
  6. Connect test light between BCM harness connector C3, terminals "B" (Orange wire) and "D" (Black wire). If test light comes on, go to next step. If test light does not come on, go to step  12 .
  7. Disconnect BCM Pink 24-pin connector C2. Disconnect scan tool. Using DVOM, check resistance between BCM connector C2, terminal B5 (Light Green wire) and Data Link Connector (DLC) terminal No. 2 (Purple wire). If resistance is less than 2 ohms, go to next step. If resistance is greater than 2 ohms, go to step  13 .
  8. Turn ignition off. Reinstall all components or connectors. Connect scan tool. Turn ignition on. Using scan tool, attempt to establish communication with BCM. If scan tool communicates with BCM, go to step  15 . If scan tool does not communicate with BCM, go to step  14 .
  9. Scan tool is unable to communicate with vehicle systems because of a malfunction in class 2 data line. Go to SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DATA LINE  . After malfunction is repaired, go to step  1 .
  10. Repair short to ground in Orange wire between BCM connector C3 and instrument panel fuse block. Go to step  1 .
  11. Repair poor connection or open in Orange wire between BCM connector C3 and instrument panel fuse block. Go to step  1 .
  12. Repair poor connection or open in Black wire between BCM connector C3 and ground. Go to step  1 .
  13. Repair poor connection or open in Light Green or Purple wire between BCM connector C3, splice pack SP205 and DLC. Go to step  1 .
  14. Replace BCM. See BODY CONTROL MODULE (BCM)  under REMOVAL & INSTALLATION. Reprogram BCM. See NEW BCM SETUP  under PROGRAMMING. Go to step  1 .
  15. Using scan tool, check for current BCM DTCs. See BCM DTC DEFINITIONS  under SELF-DIAGNOSTIC SYSTEM. If no DTCs exist, go to step  19 . If any current BCM DTCs exist, go to next step.
  16. Using scan tool, check for history BCM DTCs. See BCM DTC DEFINITIONS  under SELF-DIAGNOSTIC SYSTEM. History DTCs indicate an intermittent condition. See DIAGNOSTIC AIDS  . If any history BCM DTCs are present, go to next step. If no history DTCs are present, go to step  18 .
  17. Repair current DTCs first and then history DTCs. If more than one DTC is present, either current or history, start with lowest number and proceed. After repairs, go to step  1 .
  18. Repair current DTCs. If more than one DTC is present, start with lowest number and proceed. After repairs, go to step  1 .
  19. Using scan tool, check for history BCM DTCs. See BCM DTC DEFINITIONS  under SELF-DIAGNOSTIC SYSTEM. History DTCs indicate an intermittent condition. See DIAGNOSTIC AIDS  . If no DTCs exist, system is operating properly. If any current BCM DTCs exist, go to next step.
  20. Repair history DTCs. If more than one DTC is present, start with lowest number and proceed. After repairs, go to step  1 .
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