Draining Procedure

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

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.

Follow the steps below in order to remove the stater/generator control module (SGCM) tank fill cap.
1. Slowly rotate the cap counterclockwise.
2. Stop rotating and allow the hissing to stop.
3. After all the hissing stops, continue turning counterclockwise in order to remove the cap.

Fig 1: View Of SGMC Coolant Pump Components

Courtesy of GENERAL MOTORS CORP.

Remove the grille from the vehicle. Refer to Grille Replacement (GMC) or Grille Replacement (Chevrolet) in Exterior Trim.
Place a drain pan under the SGCM radiator.
Remove the SGCM coolant pump outlet hose from the radiator. Refer to Coolant Pipe Quick Connect Fitting - Starter/Generator Control Module .
Drain the cooling system.
Inspect the coolant.
Follow the appropriate procedure based on the condition of the coolant.
- Normal in appearance-Follow the filling procedure.
- Discolored-Follow the flush procedure. Refer to Flushing - Starter/Generator Control Module .