GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 24460-01 Cooling System Pressure Tester
    •  J 46143 Cooling System Adapter

    Caution: To avoid being burned, do not remove the starter/generator control module (SGCM) cap while the SGCM is hot. The cooling system will release scalding fluid and steam under pressure if the SGCM cap is removed while the SGCM is still hot.


    Object Number: 1206674  Size: SH
  1. Follow the steps below in order to remove the starter/generator control module (SGCM) coolant tank cap.
  2. 1.1. Slowly rotate the cap counterclockwise.
    1.2. Stop rotating and allow the hissing to stop.
    1.3. After all the hissing stops, continue turning counterclockwise in order to remove the cap.
  3. Test the operation of the pressure cap. Refer to Pressure Cap Testing - Starter/Generator Control Module .
  4. Wash the pressure cap mating surface with water.
  5. Use the J 24460-01 with the J 46143 in order to apply pressure to the cooling system.
  6. Important: Do not exceed the pressure cap rating.

  7. The cooling system should hold the rated pressure for at least 2 minutes.
  8. Observe the gage for any pressure loss.

  9. Repair any leaks as required.