GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 1998156  Size: SH
  1. Disconnect the hybrid battery. Refer to Hybrid Battery Service Disconnect/Connect .
  2. Drain the cooling system. Refer to Cooling System Draining and Filling .
  3. Unclip the battery positive cable jumper block (1) from the engine control module (ECM) bracket (4).
  4. Disconnect the ECM electrical connectors (2) and the transmission control module (TCM) electrical connector (3).

  5. Object Number: 1998167  Size: SH
  6. Remove the ECM bracket bolts (1), nuts (2) and ECM bracket (3).

  7. Object Number: 1998181  Size: SH
  8. Remove the generator control module cover bolts (1) and cover (2).

  9. Object Number: 1998192  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.

  10. Check the generator control module for voltage potential, in order to ensure that the module has been disabled.
  11. 7.1. Measure from the 36-volt positive terminal (3) to a known good chassis ground. The voltage should be less than 3 volts.
    7.2. Measure from the 12-volt positive terminal (4) to a known good chassis ground. The voltage should be less than 3 volts.
    7.3. 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.

  12. Verify that the generator control module 3-phase cables are disabled.
  13. 8.1. Measure from each phase 1, 2 and 3 connection (1) to a known good chassis ground. The voltage should be less than 3 volts.
    8.2. After verifying that there is no voltage present, the generator control module 3-phase cables can now be removed from the generator control module.
    8.3. If 3 volts or more is present, repeat the disconnect procedure. Refer to Hybrid Battery Service Disconnect/Connect .

    Object Number: 1999097  Size: SH
  14. Remove the battery positive terminal block nuts (1) and reposition the battery positive terminal block (2).
  15. Remove the 3-phase cable terminal block nuts (3) and reposition the 3-phase cable terminal block (4).

  16. Object Number: 1998402  Size: SH
  17. Disconnect the generator control module electrical connectors (1).
  18. Disconnect the 2 coolant hoses from the generator control module.

  19. Object Number: 1998501  Size: SH
  20. Remove the following components:
  21. • Fusible link nut (1)
    • Fusible link bolt (2)
    • 36-volt battery cable nut (3)
    • 36-volt battery cable nut (4)
    • Ground strap nut (5)

    Object Number: 1998511  Size: SH
  22. Remove the generator control module bracket nut (1).
  23. Remove the generator control module and bracket as an assembly.

  24. Object Number: 1998530  Size: SH
  25. Remove the generator control bracket bolts (1) and the generator control module bracket (2).
  26. If replacing the generator control module, remove the transaxle auxiliary pump control module. Refer to Auxiliary Fluid Pump Control Module Replacement .

Installation Procedure

    Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1998530  Size: SH
  1. Install the generator control bracket bolts (1) and the generator control module bracket (2).
  2. Tighten
    Tighten the bolt to 10 N·m (89 lb in).


    Object Number: 1998511  Size: SH
  3. Install the generator control module bracket nut (1).
  4. Tighten
    Tighten the bolts to 25 N·m (19 lb ft).


    Object Number: 1998501  Size: SH
  5. Install the following components:
  6. • Fusible link nut (1)
    • Fusible link bolt (2)
    • 36-volt battery cable nut (3)
    • 36-volt battery cable nut (4)
    • Ground strap nut (5)

    Tighten
    Tighten the nuts and bolts to 10 N·m (89 lb in).


    Object Number: 1998402  Size: SH
  7. Connect the 2 coolant hoses to the generator control module.
  8. Connect the generator control module electrical connectors (1).

  9. Object Number: 1999097  Size: SH
  10. Install the 3-phase cable terminal block (4) and nuts (3).
  11. Install the battery positive terminal block (2) and nuts (1).
  12. Tighten
    Tighten the nuts to 10 N·m (89 lb in).


    Object Number: 1998181  Size: SH
  13. Install the generator control module cover bolts (1) and cover (2).
  14. Tighten
    Tighten the bolt to 10 N·m (89 lb in).


    Object Number: 1998167  Size: SH
  15. Install the ECM bracket (3), bolts (1) and nuts (2).
  16. Tighten
    Tighten the bolt to 10 N·m (89 lb in).


    Object Number: 1998156  Size: SH
  17. Connect the ECM electrical connectors (2) and the TCM electrical connectors (3).
  18. Clip in the battery positive cable jumper block (1) to the ECM bracket (4).
  19. Recharge the air conditioning (A/C) system. Refer to Refrigerant Recovery and Recharging .
  20. Fill the cooling system. Refer to Cooling System Draining and Filling .
  21. Connect the hybrid battery. Refer to Hybrid Battery Service Disconnect/Connect .
  22. If the generator control module was replaced, program the new module. Refer to Control Module References .
  23. Using a Tech 2, command an autostart in order to verify that the system is working properly.