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Home >> Cadillac >> 1998 >> Seville SLS >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Control Module >> Diagnosis & Testing >> DTC B1805: Ignition Switch Problem >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform BCM diagnostic system check. See BCM DIAGNOSTIC SYSTEM CHECK  . After performing system check, go to next step.
  2. Turn ignition on. Clear DTCs using scan tool. Turn ignition off, then on. Recheck for DTCs. If this DTC resets, go to next step. If this DTC does not reset, system is okay.
  3. Turn ignition switch to RUN position. Using scan tool, select DIM, then select INPUT MENU, then check inputs RUN, ACC, UNLOCK and CRANK. If scan tool indicates that each input is active (corresponds to ignition switch position), go to step 20). If scan tool does not indicate that each input is active, go to next step.
  4. Turn ignition off. Disconnect DIM harness connector C1. Using DVOM, connect DVOM between ground and DIM harness connector terminal A3 (Pink wire). See WIRING DIAGRAMS  . Turn ignition switch to RUN, then to START position. Check DVOM reading. If battery voltage is present, go to step 7). If battery voltage is not present, go to next step.
  5. Check Pink wire for open or short to ground. If circuit is faulty, go to next step. If circuit is okay, go to step 19).
  6. Repair Pink wire circuit. After repairs, go to step 21).
  7. Connect DVOM between ground and DIM harness connector terminal A2 (Brown wire). Turn ignition switch RUN, then to ACC position. Check DVOM reading. If battery voltage is present, go to step 10). If battery voltage is not present, go to next step.
  8. Check for open or short in Brown wire. If circuit is faulty, go to next step. If circuit is okay, go to step 19).
  9. Repair open or short in Brown wire. After repairs, go to step 21).
  10. Connect DVOM between ground and DIM harness connector terminal B2 (Yellow wire). Turn ignition switch to START position. Check DVOM reading. If battery voltage is present, go to step 13). If battery voltage is not present, go to next step.
  11. Check for open or short in Yellow wire. If circuit is faulty, go to next step. If circuit is okay, go to step 19).
  12. Repair Yellow wire. After repairs, go to step 21).
  13. Connect DVOM between ground and DIM harness connector terminal B1 (Orange wire). Turn ignition switch to RUN position. Check DVOM reading. If battery voltage is present, go to step 16). If battery voltage is not present, go to next step.
  14. Check for open or short to ground in Orange wire. If circuit is faulty, go to next step. If circuit is okay, go to step 19).
  15. Repair Orange wire. After repairs, go to step 21).
  16. Connect DVOM between ground and DIM harness connector terminal A1 (White wire). Turn ignition switch to START, then RUN position. Check DVOM reading. If battery voltage is present, go to step 20). If battery voltage is not present, go to next step.
  17. Check for open or short to ground in White wire. If circuit is faulty, go to next step. If circuit is okay, go to step 19).
  18. Repair White wire. After repairs, go to step 21).
  19. Check for poor terminal contact at ignition switch connector. Repair as necessary. If terminal connector is okay, replace ignition switch. After repairs, go to step 21).
  20. Check for poor terminal contact at DIM harness connector. Repair as necessary. If terminal contact is okay, replace DIM. Program DIM. See BCM PROGRAMMING/RPO CONFIGURATION  . After programming DIM, go to next step.
  21. Turn ignition off. Reconnect components and connectors. Turn ignition on. Clear DTCs. After clearing DTCs, perform BCM diagnostic system check. See BCM DIAGNOSTIC SYSTEM CHECK  .
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