Toyota Yaris Owner's Manual page 340

340
7-3. Do-it-yourself maintenance
Engine coolant
The coolant level is satisfactory if it is between the "FULL" and "LOW"
lines on the reservoir when the engine is cold.
Gasoline engine

1
Reservoir cap
2
"FULL" line
3
"LOW" line
If the level is on or below the "LOW" line, add coolant up to the "FULL"
line. (P. 458)

Coolant selection
Only use "Toyota Super Long Life Coolant" or a similar high quality ethylene
glycol based non-silicate, non-amine, non-nitrite, and non-borate coolant with
long-life hybrid organic acid technology.
"Toyota Super Long Life Coolant" is a mixture of 50% coolant and 50% deion-
ized water. (Minimum temperature: -35C [-31F])
For more details about coolant, contact any authorized Toyota dealer or
repairer, or another duly qualified and equipped professional.

If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine coolant reservoir caps, drain cock
and water pump.
If you cannot find a leak, have any authorized Toyota dealer or repairer, or
another duly qualified and equipped professional test the cap and check for
leaks in the cooling system.
Diesel engine
