Fiat 500 ABARTH 2015 Owner's Manual page 365

• Mixing engine coolant (antifreeze) types is not recom-
mended and can result in cooling system damage. If
HOAT and OAT coolant are mixed in an emergency,
have a authorized dealer drain, flush, and refill with
OAT coolant (conforming to MS.90032) as soon as
possible.
Cooling System Pressure Cap
The cap must be fully tightened to prevent loss of engine
coolant (antifreeze) and to ensure that engine coolant
(antifreeze) remains pressurized.
The cap should be inspected and cleaned if there is any
accumulation of foreign material on the sealing surfaces.
MAINTAINING YOUR VEHICLE 363
WARNING!
• The warning words "DO NOT OPEN HOT" on the
cooling system pressure cap are a safety precaution.
Never add engine coolant (antifreeze) when the
engine is overheated. Do not loosen or remove the
cap to cool an overheated engine. Heat causes
pressure to build up in the cooling system. To
prevent scalding or injury, do not remove the
pressure cap while the system is hot or under
pressure.
• Do not use a pressure cap other than the one
specified for your vehicle. Personal injury or en-
gine damage may result.
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