Parts for your 2020 Toyota Vitz|yaris-Thermostat

2020 Toyota Vitz / Yaris Thermostat — What it does and when to replace it

Yes, the 2020 Toyota Vitz/Yaris uses a coolant thermostat. This isn’t an optional extra — it’s a standard cooling-system component on both the late XP130 Vitz/Yaris (1KR-FE, 1NR-FE, 2NR-FKE and hybrid 1NZ-FXE) and the 2020-on Yaris (M15A engines) sold in AU/NZ. Toyota’s Technical Information System (TIS) service manuals include specific removal/installation and inspection procedures for the thermostat on these models, and Toyota’s Electronic Parts Catalog (EPC) lists the thermostat within the Water Outlet/Thermostat assemblies for KSP/NSP/NHP130 and XP210 series vehicles.

On this car, the thermostat’s job is simple but crucial: it helps the engine warm up quickly, then keeps coolant temperature steady by opening and closing as needed. Faster warm-up means better fuel economy, lower emissions, and consistent heater performance on cold starts. Once at temp, a healthy thermostat keeps the gauge rock-solid and prevents overcooling on the open road.

While Toyota doesn’t set a fixed replacement interval, a thermostat is a wear item. It’s smart to inspect or replace it proactively when:

• Doing a coolant change, water pump, or timing/cooling system work
• The heater’s lukewarm, fuel use has crept up, or the gauge hangs low (stuck open)
• The engine overheats or the upper hose stays cold too long (stuck closed)
• You’ve had any major overheat event

For the 2020 Yaris in Australia and New Zealand (M15A engines), the thermostat is typically housed in the water inlet/outlet assembly with an O-ring seal. The earlier Vitz/Yaris engines are similar — a wax-pellet type thermostat in the housing. Always use a genuine or high-quality OEM-spec unit and a new gasket/O-ring. Don’t smear silicone around it, the right seal and clean faces do the job.

When refilling, use Toyota Super Long Life Coolant (pink) in the correct premix, bleed air carefully, and run the radiator fan cycle to verify stable temperature. If a temperature gauge wanders, the cabin heat goes off and on, or there’s gurgling in the heater core, there’s likely air in the system — rebleed it. A workshop scan tool can help confirm coolant temp and fan operation, but anyone handy with spanners can visually check for leaks, hose condition, and steady hose warmth after warm-up. As always, follow the Toyota service manual torque specs and procedures for the specific engine code in your Vitz/Yaris.

Popular questions

Does a 2020 Toyota Vitz/Yaris actually have a thermostat?
Yes. Toyota’s TIS repair manuals and the Toyota EPC list a thermostat for the XP130 Vitz/Yaris (including hybrid) and the 2020 AU/NZ Yaris (XP210). It’s a normal part of the cooling system.

When should the thermostat be replaced on a 2020 Vitz/Yaris?
Replace it if there are symptoms (overheating, slow warm-up, erratic temps), after any serious overheat, or while doing related cooling work. Many owners choose to fit a new thermostat preventatively around high mileage or during a coolant/water pump service.

What coolant should be used after changing the thermostat?
Use Toyota Super Long Life Coolant (pink) in the correct premix. Refill and bleed per the Toyota procedure to avoid air pockets and temperature swings.