Parts for your 2020 Toyota Vitz|yaris-Temperature sensors

Temperature sensors on the 2020 Toyota Vitz/Yaris

Based on Toyota’s technical publications, temperature sensors are absolutely used on the 2020 Toyota Vitz/Yaris. Toyota New Car Features (NCF) for the XP210 series and the Toyota Repair Manual covering M15A-FKS/M15A-FXE engines and the CVT note several temperature sensors: the engine coolant temperature (ECT) sensor, intake air temperature (IAT) sensor (integrated with the MAF on many trims), ambient air temperature sensor, A/C evaporator temperature sensor, and CVT fluid temperature sensor. Their presence is also reflected in OBD-II diagnostics (e.g., P0117/P0118 for ECT, P0112/P0113 for IAT, P0072/P0073 for ambient). That means temperaturesensors are relevant, fitted, and vital to how this Yaris runs and protects itself.

In day-to-day driving, these sensors let the engine and transmission control units keep things sweet. The ECT tells the ECU how warm the engine is so it can adjust fuelling, ignition timing, idle speed, and when to switch the radiator fans on. The IAT helps fine-tune the air–fuel mix. The ambient and evaporator sensors guide climate control to hit the cabin temperature target without fogging the screen. The CVT fluid temperature sensor protects the transmission by managing line pressure and shift strategy, especially on hot days or long climbs common across Aus and NZ.

They’re not routine “replace at X kilometres” items, but they do deserve attention during servicing. Smart shops will scan live data to confirm the ECT tracks cold starts to operating temp smoothly (roughly ambient up to about 90–100°C), the fans cut in predictably, and the IAT reads close to ambient when the engine’s cold. If a check engine light pops up with the codes mentioned above, or you see hard cold starts, high idle, the temp gauge behaving oddly, A/C that’s too hot or too cold, or a CVT that feels doughy after a hill, a temperaturesensor could be the culprit.

• Keep coolant fresh (Toyota Super Long Life Coolant, pink) and at the right mixture, old coolant can foul the ECT.
• Inspect connectors for green crust or moisture, poor earths and cracked plugs cause flaky readings.
• Clean the IAT/MAF with proper MAF cleaner only—never use brake cleaner.
• When replacing an ECT, expect some coolant loss, use a new seal, torque to spec, then bleed air from the system.
• CVT fluid temp issues? Verify fluid level and condition with the factory procedure—temperature matters during level checks.

Quality genuine or OE-equivalent sensors tend to last, so replacement is typically event-driven, not interval-based. A quick scan and a few voltage/ohm checks beat guesswork every time.

Where is the engine coolant temperature sensor on a 2020 Toyota Vitz/Yaris?

On most 2020 Yaris models, the ECT sensor threads into a coolant passage on the cylinder head or thermostat housing area, near the top front of the engine. It’s a small two-pin sensor. Access is usually from above once the engine cover is off, always let the engine cool before unplugging it to avoid hot coolant spray.

Do temperature sensors need routine replacement on this model?

No. Toyota doesn’t schedule them as routine replacements. Replace only if diagnostics point to a fault—abnormal live data, out-of-range resistance, or relevant DTCs. Preventive care means good coolant, clean connectors, and proper MAF/IAT cleaning during air filter services.

What symptoms suggest a bad temperature sensor on a 2020 Yaris?

Clues include long cold starts, poor fuel economy, rough idle, radiator fans running constantly, the temp gauge not behaving normally, A/C that won’t regulate, or CVT performance changes when hot. A scan tool showing implausible readings (e.g., -40°C or 130°C on a cold start) is a dead giveaway.