LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2001 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> Body & Frame >> Door Locks >> Power Door Lock System >> System Tests >> Test F: Power Door Unlock Inoperative, Lock Operates

Test F: Power Door Unlock Inoperative, Lock Operates

  1. If Diagnostic System Check has been performed, go to next step. If Diagnostic System Check has not been performed, perform DOOR SYSTEM DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
  2. Actuate each door lock switch, one at a time, to UNLOCK position. If doors unlocked from each position, check for intermittent problem. If doors did not unlock from each switch, go to next step.
  3. If doors unlocked from any switch, see TEST C: POWER DOOR LOCKS INOPERATIVE-ONE DOOR OR SWITCH  . If doors did not unlock from any switch, go to next step.
  4. Install scan tool. Using scan tool, command doors to unlock. If doors unlocked, go to next step. If doors did not unlock, go to step  6 .
  5. Using scan tool, observe passenger door unlock parameter. Actuate a door lock switch to UNLOCK position. If passenger door unlock parameter changed state, go to step  20 . If passenger door unlock parameter did not change state, go to step  13 .
  6. Remove door unlock relay. Using test light connected to ground, test battery positive voltage circuit (Orange wire) on coil side of door unlock relay at fuse block. If test light illuminates, go to next step. If test light does not illuminate, go to step  18 .
  7. Using a test light connected to ground, test battery positive voltage circuit on switched side of door unlock relay (Orange wire). If test light illuminates, go to next step. If test light does not illuminate, go to step  18 .
  8. Using test light connected to ground, probe door unlock control circuit (White wire) of door unlock relay. With scan tool, command doors to unlock. If test light illuminates, go to next step. If test light did not illuminate, go to step  14 .
  9. Remove door lock relay. Using a test light connected to battery positive voltage, probe ground circuit on switched side of door lock relay at fuse block. If test light illuminates, go to next step. If test light does not illuminate, go to step  19 .
  10. Install door unlock relay. Connect a fused jumper between switched side ground circuit (Black wire) and load side (Tan wire) of door lock relay at fuse block. Using scan tool, command doors to unlock. If doors unlocked, go to step  12 . If doors did not unlock, go to next step.
  11. Inspect for poor connections at door unlock relay. If problem was found, repair as necessary and then go to step  21 . If problem was not found, go to step  16 .
  12. Inspect for poor connections at door lock relay. If problem was found, repair as necessary and then go to step  21 . If problem was not found, go to step  17 .
  13. Test for an open in door unlock control circuit (White wire) between BCM and door lock switches. If problem was found, repair as necessary and then go to step  21 . If problem was not found, go to step  15 .
  14. Test for an open in door lock control circuit (Light Blue wire) between BCM and door unlock relay. If problem was found, repair as necessary and then go to step  21 . If problem was not found, go to next step.
  15. Inspect for poor connections at BCM. If problem was found, repair as necessary and then go to step  21 . If problem was not found, go to step  20 .
  16. Replace door lock relay. After completing repair, go to step  21 .
  17. Replace door unlock relay. After completing repair, go to step  21 .
  18. Repair open in door lock relay battery positive voltage circuit (Orange wire). After completing repair, go to step  21 .
  19. Repair open in door lock relay ground circuit (Black wire). After completing repair, go to step  21 .
  20. Replace BCM. See BODY CONTROL MODULE  under REMOVAL & INSTALLATION. After completing repair, go to next step.
  21. Operate system in order to verify repair.
scientia non olet · About LEMON Manuals