The hybrid electronics cooling system in the vehicle is filled with a 50/50 pre-mixed DEX-COOL® coolant and deionized water. The following explains the cooling system and how to add coolant when it is low.
If there is a problem with hybrid electronics overheating, see Hybrid Overheating.
A 50/50 mixture of clean, deionized water and DEX-COOL® coolant will:
| • | Give freezing protection down to -34°F (-37°C). |
| • | Give boiling protection up to 265°F (129°C). |
| • | Protect against rust and corrosion. |
| • | Help keep the proper hybrid electronics temperature. |
What to Use
Use a mixture of one-half clean, deionized water and one-half DEX-COOL® coolant which will not damage aluminum parts. If this coolant mixture is used, there is no need to add anything else.
Caution: Adding only water to the cooling system can be dangerous. Water, or some other liquid such as alcohol, can boil before the proper coolant mixture. The vehicle coolant warning system is set for the proper coolant mixture. With water or the wrong mixture, the hybrid electronics could get too hot, but there would be no overheat warning. The hybrid electronics would overheat and someone could be burned. Only use a 50/50 mixture of clean, deionized water and DEX-COOL® coolant. Failure to use deionized water will damage hybrid electronics components.
If coolant has to be added more than four times a year, have the dealer/retailer check the hybrid cooling system.
Checking Coolant
The hybrid coolant surge tank is located on the driver side of the engine compartment. See Engine Compartment Overview for more information on location.
Caution: Coolant from a hot cooling system can cause serious injury. The coolant is under pressure, and if the coolant surge tank pressure cap is turned-even a little-the coolant can come out. Never turn the cap when the cooling system, including the coolant surge tank pressure cap, is hot. Wait for the cooling system and coolant surge tank pressure cap to cool if the pressure cap ever has to be turned.
The vehicle must be on a level surface. When your engine is cold, the coolant level should be between the MIN and MAX lines.
Adding Coolant
If the vehicle needs more coolant, add the proper DEX-COOL® coolant mixture at the surge tank, but only when the hybrid electronics are cool. See Cooling System.
When replacing the pressure cap, make sure it is hand-tight and fully seated.
