Hybrid Drive System

Generator Control Module Cooling System Draining and Filling

Special Tools
* J 26568 Coolant and Battery Tester
* J 38185 Hose Clamp Pliers

Draining Procedure

Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.

1. Follow the steps below in order to remove the surge 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.

2. Raise and support the vehicle. Refer to Vehicle Lifting.
3. Place a drain pan under the generator control module coolant pump hose. Refer to Generator Control Module Coolant Pump Hose Replacement (Pump to Pump) Generator Control Module Coolant Pump Hose Replacement (Pump to Radiator).
4. Using the J 38185, reposition the generator control module coolant pump hose clamp.
5. Remove the generator control module coolant pump hose from the coolant pump.
6. Drain the coolant.
7. Place a drain pan under the generator control module coolant inlet hose. Refer to Generator Control Module Coolant Inlet Hose Replacement.
8. Using the J 38185, reposition the generator control module coolant inlet hose clamp.
9. Drain the coolant.

Filling Procedure

Notice: The procedure below must be followed. Improper coolant level could result in a low or high coolant level condition, causing engine damage.

1. Install the generator control module coolant pump hose.
2. Using the J 38185, reposition the generator control module coolant pump hose clamp.
3. Install the generator control module coolant inlet hose.
4. Using the J 38185, reposition the generator control module coolant inlet hose clamp.
5. Lower the vehicle.

Important: Use a 50/50 mixture of DEX-COOL antifreeze and deionized water.

6. Slowly fill the cooling system with a 50/50 coolant mixture. Refer to Approximate Fluid Capacities.
7. Install the coolant pressure cap.
8. Start the engine.
9. Run the engine at 2,000-2,500 RPM until the engine reaches normal operating temperature.
10. Allow the engine to idle for 3 minutes.
11. Shut the engine OFF.
12. Allow the engine to cool.
13. Top off the coolant as necessary.
14. Inspect the concentration of the generator control module coolant using the J 26568.