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Bus +/- Signals Open From Sentry Key Immobilizer Module (Skim)

  1. Turn ignition on. Using scan tool, select BODY, select BODY COMPUTER. If scan tool displays NO RESPONSE FROM BCM, go to next step. If scan tool does not display NO RESPONSE FROM BCM, go to step  16 .
  2. Using scan tool, select PASSIVE RESTRAINTS, then select AIRBAG. Monitor scan tool display. Select ANTI-LOCK BRAKES. If scan tool displays version and/or part number for either module, go to next step. If scan tool does not display version and/or part number for either module, go to COMPLETE PCI BUS FAILURE  .
  3. Remove and inspect junction block fuse No. 22. If fuse is blown, go to step  12 . If fuse is okay, go to next step.
  4. Remove and inspect junction block fuse No. 29. If fuse is blown, go to step  9 . If fuse is okay, go to next step.
  5. Turn ignition on. Using voltmeter, backprobe BCM C1 connector. Measure voltage between ground and terminals No. 1 (Black/Orange wire), 14 (Black/Orange wire) and 25 (Black wire). If voltage is present on any circuit, repair suspect open circuit. If no voltage is present on all circuits, go to next step.
  6. Turn ignition off. Disconnect negative battery cable. Remove BCM from rear of junction block. Reconnect battery negative cable. Turn ignition on. Measure voltage between ground and terminal No. 25 on junction block internal BCM connector. If voltage is greater than 10 volts, reconnect all components and go to next step. If voltage is 10 volts or less, replace junction block.
  7. Connect Scope Input Cable (CH 7058) to channel No. 1 connector on scan tool. Connect Red and Black test probe cable with Probe Adapter (CH7062) to scope input cable. Select DRB STANDALONE. Select LAB SCOPE, then LIVE. Select 12 VOLT SQUARE WAVE. Press F2 for scope. Press F2 and use down arrow to set voltage range to 20 volts. Press F2. Connect Black lead to chassis ground. Backprobe Red lead to terminal No. 15 (Yellow/Violet/White wire) on BCM C1 harness connector. Turn ignition on. If voltage displayed on scan tool lab scope pluses from zero to about 7.5 volts, replace BCM. If voltage is zero volts, repair open Yellow/Violet/White wire.
  8. Turn ignition off. Disconnect negative battery cable. Remove BCM from rear of junction block. Reconnect battery negative cable. Turn ignition on. Measure voltage between ground and terminal No. 5 on junction block internal BCM connector. If voltage is greater than 10 volts, replace BCM. If voltage is 10 volts or less, replace junction block.
  9. Turn ignition on. Using voltmeter, backprobe BCM C1 connector. Measure voltage between ground and terminals No. 1 (Black/Orange wire), 14 (Black/Orange wire) and 25 (Black wire). If voltage is present on any circuit, repair suspect open circuit. If no voltage is present on all circuits, go to next step.
  10. Turn ignition off. Disconnect negative battery cable. Remove BCM from rear of junction block. Reconnect battery negative cable. Measure resistance between ground and fused ignition switch output terminal on junction block fuse No. 29 socket. If resistance is less than 5 ohms, repair fused ignition switch output circuit for short to ground. If resistance is 5 ohms or greater, go to next step.
  11. Disconnect negative battery cable. Connect BCM to rear of junction block. Reconnect battery negative cable. Measure resistance between ground and fused ignition switch output terminal on junction block fuse No. 29 socket. If resistance is less than 5 ohms, replace BCM. If resistance is 5 ohms or greater, replace defective fuse.
  12. Remove and inspect junction block fuse No. 29. If fuse is blown, go to step 14)  . If fuse is okay, go to next step.
  13. Turn ignition on. Using voltmeter, backprobe BCM C1 connector. Measure voltage between ground and terminals No. 1 (Black/Orange wire), 14 (Black/Orange wire) and 25 (Black wire). If voltage is present on any circuit, repair suspect open circuit. If no voltage is present on all circuits, go to next step.
  14. Turn ignition off. Disconnect negative battery cable. Remove BCM from rear of junction block. Reconnect battery negative cable. Measure resistance between ground and terminal No. 5 on junction block internal BCM connector. If resistance is less than 5 ohms, replace junction block. If resistance is 5 ohms or greater, go to next step.
  15. Disconnect negative battery cable. Connect BCM to rear of junction block. Reconnect battery negative cable. Measure resistance between ground and fused ignition switch output terminal on junction block fuse No. 22 socket. If resistance is less than 5 ohms, replace BCM. If resistance is 5 ohms or greater, replace defective fuse.
  16. Inspect junction block fuses No. 7 and 22. If fuse No. 7 is blown, go to next step. If fuse No. 22 is blown, go to step 23. If both fuses are okay, go to step 18.
  17. Turn ignition off. Disconnect negative battery cable. Disconnect SKIM connector. Using ohmmeter, measure resistance between ground and terminal No. 1 (Pink wire) on SKIM harness connector. If resistance is less than 5 ohms, repair Pink wire for short to ground. Replace defective fuse. If resistance is 5 ohms or greater, replace defective fuse.
  18. Measure resistance between ground and terminal No. 2 (Black/Orange wire) on SKIM harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or greater, repair open Black/Orange wire.
  19. Ensure battery is connected. Using voltmeter, measure voltage between ground and terminal No. 1 (Pink wire) on SKIM harness connector. If voltage is 10 volts or less, repair open Pink wire. If voltage is greater than 10 volts, go to next step.
  20. Remove and inspect junction block fuse No. 22. If fuse is blown, go to step  23 . If fuse is okay, go to next step.
  21. Turn ignition on. Using voltmeter, measure voltage between ground and terminal No. 3 (Dark Blue/White wire) on SKIM harness connector. If voltage is 10 volts or less, repair open Dark Blue/White wire. If voltage is greater than 10 volts, go to next step.
  22. Ensure SKIM connector is disconnected. Connect Scope Input Cable (CH 7058) to channel No. 1 connector on scan tool. Connect Red and Black test probe cable with Probe Adapter (CH7062) to scope input cable. Select DRB STANDALONE. Select LAB SCOPE, then LIVE. Select 12 VOLT SQUARE WAVE. Press F2 for scope. Press F2 and use down arrow to set voltage range to 20 volts. Press F2. Connect Black lead to chassis ground. Backprobe Red lead to terminal No. 5 (Yellow/Violet/Brown wire) on SKIM harness connector. Turn ignition on. If voltage displayed on scan tool lab scope pluses from zero to about 7.5 volts, replace BCM. If voltage is zero volts, repair open Yellow/Violet/Brown wire.
  23. Turn ignition off. Using ohmmeter, measure resistance between ground and terminal No. 3 (Dark Blue/White wire) on SKIM harness connector. If resistance is less than 5 ohms, repair Dark Blue/White wire for short to ground. Replace fuse No. 22. If resistance is 5 ohms or greater, replace fuse No. 22.
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