Toyota Yaris Owner's Manual page 459

NOTICE
■
When adding engine/power control unit coolant
Wait until the hybrid system has cooled down before adding engine/power
control unit coolant.
When adding coolant, do so slowly. Adding cool coolant to a hot hybrid sys-
tem too quickly can cause damage to the hybrid system.
■
To prevent damage to the cooling system
Observe the following precautions.
●
Avoid contaminating the coolant with foreign matter (such as sand or dust
etc.).
●
Do not use any coolant additives.
YARIS_HV_OM_Europe_OM52G76E
8-2. Steps to take in an emergency
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