2010 Toyota Highlander Owners Manual - Page 559

5-2. Steps to take in an emergency STEP 4 After the hybrid system has cooled down, check the engine coolant level and inspect the cooling system for leaks. Engine coolant reservoir Radiator STEP 5 If necessary, add engine coolant up to the "FULL" line. Water can be used in an emergency if engine coolant is unavailable. (→P. 545) 5 When trouble arises 535