GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  2. Remove the cover from the underhood electrical center.

  3. Object Number: 891886  Size: SH
  4. Remove the underhood positive battery terminal lug (1).
  5. Important: Take note of the positioning of the positive battery cables before disconnecting the cables.

  6. Disconnect the positive battery cables (2) from the underhood electrical center.
  7. Remove the electric power steering (EPS) cable nut from the underhood electrical center.
  8. Disconnect the EPS cable (3) from the underhood electrical center.

  9. Object Number: 891888  Size: SH
  10. Release the engine wiring harness retainer (1), next to the engine control module (ECM). Reposition the wiring harness (2) toward the engine.

  11. Object Number: 891889  Size: SH
  12. Disconnect the outboard side electrical connector (1) from the ECM. Position the connector aside.

  13. Object Number: 891890  Size: SH
  14. Remove the ECM (1) from the underhood electrical center bracket, and reposition the module with harness, toward the engine.

  15. Object Number: 891892  Size: SH
  16. Remove the automatic transmission control module (TCM), if equipped, from the underhood electrical center bracket, and reposition the module with harness, toward the engine.

  17. Object Number: 891907  Size: SH
  18. Release the EPS cable retainer from the underhood electrical center bracket.
  19. Release the forward lamp harness retainer from the outboard side of the ECM tray.
  20. Release the surge tank inlet hose clip from the electrical center bracket.
  21. Remove the cooling system surge tank mounting nut.
  22. Remove the underhood electrical center bracket mounting nut.
  23. Remove the electrical center bracket mounting bolt.
  24. Lift the bracket off of the studs and reposition the bracket slightly toward the engine.

  25. Object Number: 891894  Size: SH
  26. Release the 3 locking tabs (1) securing the underhood electrical center (2) to the electrical center bracket.

  27. Object Number: 891899  Size: SH
  28. Lift the electrical center (1) away from the bracket and carefully position the electrical center (1) up and outboard, toward the hood hinge. Secure the electrical center (1) in position.

  29. Object Number: 891897  Size: SH
  30. Lift the surge tank hose (1) slightly and move the electrical center bracket (2) toward the front of the vehicle.
  31. Remove the bracket (2) from the vehicle.

Installation Procedure


    Object Number: 891897  Size: SH
  1. Position the electrical center bracket (2) to the vehicle.
  2. Lift the surge tank inlet hose (1) slightly and move the electrical center bracket (2) toward the rear of the vehicle, just inboard of the installed position.

  3. Object Number: 891894  Size: SH
  4. Release the retainer from the underhood electrical center and position the electrical center (2) to the electrical center bracket.
  5. Important: Ensure that the wiring harnesses are not pinched when securing the electrical center to the bracket.

  6. Secure the underhood electrical center locking tabs (1) to the electrical center bracket.

  7. Object Number: 891907  Size: SH
  8. Position the electrical center bracket onto the studs at the surge tank and on the frame rail.
  9. Install the underhood electrical center bracket mounting bolt. Do not tighten yet.
  10. Notice: Refer to Fastener Notice in the Preface section.

  11. Install the underhood electrical center bracket mounting nut.
  12. Tighten
    Tighten the nut to 10 N·m (89 lb in).

  13. Install the cooling system surge tank mounting nut.
  14. Tighten
    Tighten the nut to 10 N·m (89 lb in).

  15. Tighten the underhood electrical center bracket mounting bolt.
  16. Tighten
    Tighten the bolt to 25 N·m (18 lb ft).

  17. Secure the forward lamp harness retainer to the outboard side of the ECM tray.
  18. Secure the EPS cable retainer to the underhood electrical center bracket.

  19. Object Number: 891892  Size: SH
  20. Install the TCM, if equipped, with harness to the underhood electrical center bracket.

  21. Object Number: 891890  Size: SH
  22. Install the ECM (1) with harness, to the underhood electrical center bracket.

  23. Object Number: 891889  Size: SH
  24. Connect the outboard side electrical connector (1) to the ECM.

  25. Object Number: 891888  Size: SH
  26. Install the engine wiring harness (2) to the retainer (1), next to the ECM. Secure the harness retainer (1).

  27. Object Number: 891886  Size: SH
  28. Connect the EPS cable (3) to the underhood electrical center.
  29. Install the electric power steering cable nut.
  30. Tighten
    Tighten the nut to 10 N·m (89 lb in).

  31. Connect the positive battery cables (2) to the underhood electrical center. Position the cables as noted previously.
  32. Install the underhood positive battery terminal lug (1).
  33. Tighten
    Tighten the lug to 15 N·m (11 lb ft).

  34. Install the cover to the underhood electrical center.
  35. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .