GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 1813960  Size: SH
  1. Disconnect the hybrid battery. Refer to Hybrid Battery Service Disconnect/Connect .
  2. Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement .
  3. Remove the drive belt. Refer to Drive Belt Replacement .
  4. Remove the engine wiring harness auxiliary bussed electrical center (BEC) (1) from the wiring harness relay block bracket.
  5. Remove the engine wiring harness clip (2) from the positive battery cable bracket.
  6. Reposition the engine wiring harness auxiliary BEC (1) out of the way.

  7. Object Number: 1814045  Size: SH
  8. Remove the underhood bussed electrical center (UBEC) cover (1).
  9. Remove the positive battery cable lead to UBEC nut and remove the 3 positive cables from the stud.
  10. Loosen the UBEC bolts (2), once loose, tap the bolts once, in order to disengage the bolt from the electrical connectors.
  11. Disconnect the 3 electrical connectors from the rear of the UBEC. Note the color and location of each connector.
  12. Disengage the UBEC retaining tabs on the 4 corners and remove the UBEC.

  13. Object Number: 1813958  Size: SH
  14. Remove the forward lamp wiring harness electrical connector (1) from the positive battery cable bracket.

  15. Object Number: 1814035  Size: SH
  16. Remove the forward lamp wiring harness clips (2) from the positive battery cable bracket.
  17. Remove the forward lamp wiring harness UBEC electrical connector (1) from the UBEC bracket and secure out of the way.

  18. Object Number: 1814036  Size: SH
  19. Remove the engine wiring harness clip (2) from the battery tray.
  20. Remove the engine wiring harness UBEC electrical connector (1) from the UBEC bracket and secure out of the way.

  21. Object Number: 1814033  Size: SH
  22. Remove the forward lamp wiring harness electrical connector (2) from the battery tray.
  23. Remove the body wiring harness UBEC electrical connector (1) from the UBEC bracket and secure out of the way.

  24. Object Number: 1820891  Size: SH
  25. Remove the 12-volt positive battery cable clips (4) from the UBEC bracket.
  26. Remove the 12-volt positive battery cable clip (3) from the positive battery cable bracket.

  27. Object Number: 1814038  Size: SH
  28. Remove the UBEC bracket bolts (1) and bracket.

  29. Object Number: 1816288  Size: SH
  30. Remove the A/C compressor and condenser hose nut (1) from the generator control module bracket stud.
  31. Remove the positive battery cable bracket (2) from the stud.

  32. Object Number: 1813962  Size: SH
  33. Remove the engine control module (ECM) bracket from the battery hold down bracket and reposition out of the way.
  34. Remove the battery hold down bracket nuts (1, 4).
  35. Remove the wiring harness relay block bracket nut (3) and bracket (2).
  36. Remove the battery hold down retainer (5).

  37. Object Number: 1815938  Size: SH
  38. Remove the generator control module bracket bolts and stud.
  39. Remove the generator control module bracket.

  40. Object Number: 1810869  Size: SH
  41. Remove the generator control module 3-phase cable bracket to tie bar bolt.

  42. Object Number: 1816292  Size: SH

    Caution: To help avoid personal injury, additional precautions must be taken prior to working on the generator control module or the generator starter. After removing the 36V battery cables from the generator battery, remove both engine wiring harness connectors from the generator control module. Wait at least 5 minutes and then remove the generator control module cover. Verify voltage levels at all 36V, 12V, and 3-phase connections, are less than 3 volts using a DMM before proceeding.

  43. Disconnect the 2 engine wiring harness electrical connectors (1) from the generator control module.
  44. WAIT at least 5 minutes in order to allow the voltage stored in the generator control module to discharge.

  45. Object Number: 1816289  Size: SH
  46. Remove the generator control module cover bolts and cover.

  47. Object Number: 1864864  Size: SH
  48. The generator control module will have to be checked for voltage potential using a voltmeter. First, verify that the voltmeter works:
  49. 34.1. Set the voltmeter to DC voltage.
    34.2. Measure the vehicle 12-volt battery voltage.
    34.3. The meter should read greater than +12 volts DC.
  50. Now, check the generator control module for voltage potential, in order to ensure that the module has been disabled.
  51. 35.1. Measure from the 36-volt positive terminal (3) to a known good chassis ground. The voltage should be less than 3 volts.
    35.2. Measure from the 12-volt positive terminal (4) to a known good chassis ground. The voltage should be less than 3 volts.
    35.3. Measure from the ground terminal (2) to a known good chassis ground, checking for continuity.

    Caution: To help avoid personal injury, always treat the 3-phase cable and connectors as if voltage is present and as if the surface of all parts of the cable is hot.

  52. Verify that the generator control module 3-phase cables are disabled.
  53. 36.1. Measure from each phase 1, 2, and 3 connection (1) to a known good chassis ground. The voltage should be less than 3 volts.
    36.2. After verifying that there is no voltage present, the generator control module 3-phase cables can now be removed from the generator control module.

    Object Number: 1810743  Size: SH
  54. Partially raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
  55. Remove the fuel injector wiring harness electrical connector retainer (6) from the generator starter tab.
  56. Disconnect the engine wiring harness electrical connectors (2, 4) from the generator starter.

  57. Object Number: 1824552  Size: SH
  58. Remove the generator control module 3-phase cable nuts at the generator control module.

  59. Object Number: 1824553  Size: SH
  60. Remove the 12-volt positive battery cable nut (5) from the generator control module.
  61. Remove the 36-volt positive battery cable nut (2) from the generator control module.
  62. Remove the 36-volt terminal block nuts (1) from the generator control module.
  63. Lift up, remove, and reposition the 36-volt terminal block, secure the block out of the way. Discard the terminal block seal.

  64. Object Number: 1824554  Size: SH
  65. Remove the generator control module 3-phase cable terminal block nuts from the generator control module.
  66. Remove the generator control module 3-phase cable terminal block from the generator control module. Discard the terminal block seal.

  67. Object Number: 1810870  Size: SH
  68. Remove the generator starter bolts.
  69. Remove the generator starter with the generator control module 3-phase cables from the vehicle and place on a clean work surface.

  70. Object Number: 1824551  Size: SH
  71. Remove the generator starter cover bolts (1) and cover.
  72. Remove the generator control module 3-phase cable bracket bolts (2) and bracket.
  73. Remove the generator control module 3-phase cable to generator starter nuts.

  74. Object Number: 1830824  Size: SH
  75. Remove the rear generator control module 3-phase cable bolts (1).

  76. Object Number: 1830827  Size: SH
  77. Remove the generator control module 3-phase cable assembly from the generator starter.

Installation Procedure


    Object Number: 1830827  Size: SH
  1. Install the generator control module 3-phase cable assembly to the NEW generator starter.
  2. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1824551  Size: SH
  3. Install the generator control module 3-phase cable to generator starter nuts.
  4. Tighten
    Tighten the nuts to 8 N·m (71 lb in).

  5. Install the generator control module 3-phase cable bracket and bolts (2).
  6. Tighten
    Tighten the bolts to 8 N·m (71 lb in).

  7. Install the generator starter cover and bolts (1).
  8. Tighten
    Tighten the bolts to 5 N·m (44 lb in).


    Object Number: 1830824  Size: SH
  9. Install the rear generator control module 3-phase cable bolts (1).
  10. Tighten
    Tighten the bolts to 8 N·m (71 lb in).


    Object Number: 1810870  Size: SH
  11. Position the generator starter with the generator control module 3-phase cables to the vehicle and install the bolts.
  12. Tighten the generator starter bolts in the following sequence.
  13. 7.1. Front
    7.2. Bottom

    Tighten
    Tighten the bolts to 58 N·m (43 lb ft).


    Object Number: 1824554  Size: SH
  14. Place a NEW terminal block seal onto the generator control module.
  15. Install the generator control module 3-phase cable terminal block to the generator control module.
  16. Install the generator control module 3-phase cable terminal block nuts to the generator control module.
  17. Tighten
    Tighten the nuts to 8 N·m (71 lb in).


    Object Number: 1824553  Size: SH
  18. Place a NEW terminal block seal onto the generator control module.
  19. Unsecure, position and install the 36-volt terminal block to the generator control module.
  20. Install the 36-volt terminal block nuts (1) to the generator control module.
  21. Tighten
    Tighten the nuts to 10 N·m (89 lb in).

  22. Install the 36-volt positive battery cable nut (2) to the generator control module.
  23. Tighten
    Tighten the nut to 10 N·m (89 lb in).

  24. Install the 12-volt positive battery cable nut (5) from the generator control module.
  25. Tighten
    Tighten the nut to 10 N·m (89 lb in).


    Object Number: 1824552  Size: SH
  26. Install the generator control module 3-phase cable nuts at the generator control module.
  27. Tighten
    Tighten the nuts to 8 N·m (71 lb in).


    Object Number: 1810743  Size: SH
  28. Connect the engine wiring harness electrical connectors (2, 4) to the starter generator.
  29. Install the fuel injector wiring harness electrical connector retainer (6) to the starter generator tab.
  30. Lower the vehicle.

  31. Object Number: 1816289  Size: SH
  32. Install the generator control module cover and bolts.
  33. Tighten
    Tighten the bolts to 10 N·m (89 lb in).


    Object Number: 1816292  Size: SH
  34. Connect the 2 engine wiring harness electrical connectors (1) to the generator control module.

  35. Object Number: 1810869  Size: SH
  36. Install the generator control module 3-phase cable bracket bolt at the tie bar.

  37. Object Number: 1815938  Size: SH
  38. Install the generator control module bracket.
  39. Install the generator control module bracket bolts and stud.
  40. Tighten
    Tighten the bolts/stud to 10 N·m (89 lb in).


    Object Number: 1813962  Size: SH
  41. Install the battery hold down retainer (5).
  42. Install the battery hold down bracket nuts (1, 4).
  43. Tighten
    Tighten the nuts to 10 N·m (89 lb in).

  44. Install the wiring harness relay block bracket (2) and nut (3).
  45. Tighten
    Tighten the nut to 10 N·m (89 lb in).

  46. Position and install the ECM bracket to the battery hold down bracket.

  47. Object Number: 1816288  Size: SH
  48. Install the positive battery cable bracket (2) to the stud.
  49. Install the A/C compressor and condenser line nut (1) to the generator control module bracket stud.
  50. Tighten
    Tighten the nut to 20 N·m (15 lb ft).


    Object Number: 1814038  Size: SH
  51. Install the UBEC bracket, align the locator pin (2) with the hole in the battery tray.
  52. Install the UBEC bracket and bolts (1).
  53. Tighten
    Tighten the bolts to 9 N·m (80 lb in).


    Object Number: 1820891  Size: SH
  54. Install the 12-volt positive battery cable clips (4) to the UBEC bracket.
  55. Install the 12-volt positive battery cable clip (3) to the positive battery cable bracket.

  56. Object Number: 1814033  Size: SH
  57. Position and install the body wiring harness UBEC electrical connector (1) to the UBEC bracket.

  58. Object Number: 1814036  Size: SH
  59. Position and install the engine wiring harness UBEC electrical connector (1) to the UBEC bracket.
  60. Install the engine wiring harness clip (2) to the battery tray.

  61. Object Number: 1814035  Size: SH
  62. Position and install the forward lamp wiring harness UBEC electrical connector (1) to the UBEC bracket.
  63. Install the forward lamp wiring harness clips (2) to the positive battery cable bracket.

  64. Object Number: 1813958  Size: SH
  65. Install the forward lamp wiring harness electrical connector (1) to the positive battery cable bracket.

  66. Object Number: 1814045  Size: SH
  67. Install the UBEC.
  68. Connect the 3 electrical connectors to the rear of the UBEC. Ensure that the color and location of each connector is correct.
  69. Tighten the UBEC bolts (2).
  70. Tighten
    Tighten the bolts to 4 N·m (35 lb in).

  71. Install the 3 positive cables to the UBEC stud and install the positive battery cable lead nut.
  72. Tighten
    Tighten the nut to 15 N·m (11 lb ft).

  73. Install the UBEC cover (1).

  74. Object Number: 1813960  Size: SH
  75. Position and install the engine wiring harness auxiliary BEC (1) to the wiring harness relay block bracket.
  76. Install the engine wiring harness clip (2) to the positive battery cable bracket.
  77. Install the drive belt. Refer to Drive Belt Replacement .
  78. Install the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement .
  79. Connect the hybrid battery. Refer to Hybrid Battery Service Disconnect/Connect .
  80. Using a Tech 2, command an autostart in order to verify that the system is working properly.