Parts for your 2017 Toyota Vitz|yaris-Temperature sensors

2017 Toyota Vitz/Yaris Temperature Sensors

Temperature sensors are absolutely relevant and fitted on the 2017 Toyota Vitz/Yaris. Technical sources such as the Toyota Repair Manual and the 2017 Vitz/Yaris Electrical Wiring Diagram (XP130 platform), along with Toyota Techstream diagnostic data (DTC sets like P0115–P0119, P0128, P0113, and P0071), show this model uses multiple temperature sensors: the engine coolant temperature (ECT) sensor, an intake air temperature (IAT) sensor integrated in the MAF, an ambient air temperature sensor at the front of the car, an A/C evaporator thermistor, and a transmission fluid temperature sensor on CVT-equipped variants.

On this model, temperature sensors quietly keep everything in check. The ECT sensor lets the engine ECU know how hot the coolant is so it can manage cold starts, fuelling, ignition timing, radiator fan operation, and even the thermostat strategy on some variants. The IAT sensor helps the ECU adjust for air density, keeping drivability tidy from a frosty Dunedin morning to a steamy Darwin arvo. Ambient and evaporator sensors keep the climate control honest, while the CVT fluid temperature sensor protects the transmission from running too hot or too cold.

As part of regular servicing, temperature sensors aren’t a routine “replace at X km” item, but they do deserve attention:

• During coolant service (Toyota Super Long Life Coolant intervals typically 160,000 km/10 years initially, then 80,000 km/5 years), inspect the ECT sensor area for leaks, corrosion, or brittle connectors.
• Check the MAF/IAT for contamination. A quick, correct MAF clean can restore accurate IAT readings—avoid touching the sensing wire and only use proper MAF cleaner.
• Look over the front-bumper ambient sensor for damage after minor bumps, a broken bracket or exposed wiring can skew readings.
• If the A/C cycles oddly or cabin temps feel off, the evaporator thermistor and in-cabin sensor grill may need inspection or cleaning.
• CVT owners: fluid condition and correct level help keep the temp sensor readings meaningful, overheated or degraded fluid can trigger temp-related faults and limp mode.

Common clues a sensor’s on the fritz include hard cold starts, rough idle, poor fuel economy, a fan that runs constantly, a dead temp gauge, weak A/C performance, or the MIL glowing with codes like P0115, P0117, P0118, P0128, P0113, or P0071. Replacement is straightforward for the ECT and ambient sensors: disconnect the plug, relieve system pressure where needed, and swap with a quality OEM-equivalent part. Mind the sealing washer or O-ring, avoid thread sealants unless specified, and tighten to the torque in the Toyota manual. Electrical testing with a multimeter (checking resistance against the manual’s temperature/resistance table) and scan-tool live data is the smart way to confirm a fault before spinning any spanners.

Popular questions about 2017 Toyota Vitz/Yaris temperature sensors

Where is the engine coolant temperature (ECT) sensor located?
It’s typically threaded into the water outlet/thermostat housing near the cylinder head. Access varies slightly by engine (1.0L, 1.3L, 1.5L), but it’s generally on the engine’s coolant outlet with a two-pin connector. A quick look under the bonnet near the upper radiator hose usually spots it.

Do temperature sensors need regular replacement?
No, they’re not a scheduled replacement item. They’re checked when symptoms appear or during related services (coolant changes, MAF cleaning, A/C diagnostics). If testing shows out-of-spec readings or there’s physical damage or corrosion, then replacement is recommended.

What fault codes point to a bad temperature sensor on this model?
For coolant temp: P0115–P0119 and P0128 are common. For intake air temp: P0113/P0112. For ambient/climate: P0071–P0073. These codes indicate the circuit or readings are out of expected range, but proper diagnosis with live data and wiring checks is still essential.