2007 Lexus GS 450h Owners Manual - Page 495

5-2. Steps to take in an emergency If your vehicle overheats n Electric motor (traction motor) and inverter If the message "HYBRID SYSTEM OVERHEAT" is displayed on the multi-information display. n Gasoline engine If the needle of the engine coolant temperature gauge enters the red zone, the gasoline engine has probably overheated. Observe the following steps: STEP 1 STEP 2 STEP 3 STEP 4 STEP 5 Stop the vehicle in a safe place and turn off the automatic air conditioning system. Check to see if steam is coming out from under the hood. If you see steam: Stop the hybrid system and carefully lift the hood. If you do not see steam: Leave the hybrid system running and carefully lift the hood. Remove the engine compartment cover. (→P. 370) Check to see if the cooling fan is operating. If the fan is operating: Wait until the engine coolant temperature gauge begins to fall and then stop the hybrid system. If the fan is not operating: Stop the hybrid system immediately and call your local Lexus dealer. After the hybrid system has cooled down sufficiently, check the coolant level and inspect the radiator core (radiator) for any leaks. 480