LEMON Manuals: Even more car manuals for everyone
Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 515 (Hybrid/EV Cooling System) >> Diagnostic Information and Procedures >> Hybrid Cooling System Loss of Coolant

Hybrid Cooling System Loss of Coolant

WARNING: This page is about a different car, the 2012 GMC Yukon, 2012 Chevrolet Tahoe, and 2012 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
Hybrid Cooling System Loss of Coolant

Step Action Yes No
DEFINITION: The cooling system is loosing coolant either internally or externally.
1 Inspect the coolant level.
Is the coolant at the proper level?
Go to Step 13  Go to Step 2 
2 Fill the cooling system to the proper level. Refer to Generator Control Module Cooling System Draining and Filling .
Is the action complete?
Go to Step 3  -
3 Overheating can cause a loss of coolant.
Is the Hybrid Cooling system overheating?
Go to Step 11  Go to Step 4 
4 Visually inspect the hoses, pipes and hose clamps.
Are any of the hoses, clamps or pipes leaking?
Go to Step 12  Go to Step 5 
5 Visually inspect the following components:
  • Coolant surge tank
  • Coolant pressure cap
  • Drive motor generator control module
  • Air separator
  • Radiator
  • Coolant pumps

Are any of the listed components leaking?
Go to Step 12  Go to Step 6 
6
  1. Pressure test the cooling system. Refer to Hybrid Cooling System Leak Test .
  2. With the cooling system pressurized, visually inspect the components listed in step 5.
Are any leaks present?
Go to Step 12  Go to Step 7 
7 Pressure test the coolant pressure cap. Refer to Hybrid Cooling System Pressure Cap Testing .
Does the coolant pressure cap hold pressure?
Go to Step 9  Go to Step 8 
8 Replace the coolant pressure cap.
Is the repair complete?
Go to Step 13  -
9
  1. Pressure test the cooling system. Refer to Hybrid Cooling System Leak Test .
  2. With the cooling system pressurized, remove the engine cooling system pressure cap.
Does the hybrid cooling system hold pressure?
- Go to Step 10 
10 Replace the surge tank. Refer to Radiator Surge Tank Replacement (Non-HP2) , Radiator Surge Tank Replacement (HP2) .
Is the repair complete?
Go to Step 13  -
11 Repair the hybrid cooling system overheating condition. Refer to Hybrid Cooling System Overheating (Electrical) .
Is the repair complete?
Go to Step 13  -
12 Repair or replace the leaking component. Refer to the appropriate repair.
Is the repair complete?
Go to Step 13  -
13 Operate the system in order to verify the repair.
Did you find and correct the condition?
System OK Go to Step 2