Parts for your 2015 Toyota Wish-Temperature sensors

2015 Toyota Wish temperature sensors: what they do and how to look after them

Based on Toyota’s own technical literature for the ZGE2# series Wish (Repair Manual and New Car Features), the 2ZR-FAE/3ZR-FAE engines and Super CVT‑i driveline use several temperature sensors. These include the engine coolant temperature (ECT) sensor for the engine ECU, an intake air temperature (IAT) element integrated in the mass air flow sensor, a transmission fluid temperature sensor within the CVT valve body, and climate-control sensors such as ambient/outside air, in‑cabin/aspirator, and evaporator temperature sensors. Toyota Electrical Wiring Diagrams and DENSO/Aisin component documentation also detail these devices. So, temperature sensors are absolutely fitted and relevant on the 2015 Toyota Wish.

On this model, temperature sensors are the quiet achievers that keep everything running sweet. The ECT sensor lets the ECU decide fueling, ignition timing, and when to switch the radiator fans, which helps cold starts, smooth idle, and good fuel economy. The IAT sensor reports the temperature of the air coming through the intake, helping trim fuelling on hot summer days or chilly mornings. The CVT fluid temperature sensor protects the transmission by adjusting line pressure and shift strategy when the fluid is cold or getting a bit warm. For comfort, the ambient, cabin and evaporator sensors give the A/C amplifier the info it needs to avoid fogged windows and keep cabin temps steady without overworking the system.

Servicing-wise, most temperature sensors are “fit and forget” until they misreport. That said, a few easy habits go a long way:

• Coolant and connectors: Keep the cooling system healthy with the correct Toyota Super Long Life Coolant. Corroded or oil-soaked connectors at the ECT or MAF/IAT can cause dodgy readings—inspect and clean gently if needed.
• MAF/IAT care: If there’s rough idle or hesitation, a careful clean of the MAF (which houses the IAT) with proper MAF cleaner can restore accurate readings—never use brake cleaner or touch the sensing wire.
• CVT servicing: When changing CVT fluid, the level check depends on fluid temperature. A proper scan tool (e.g., Toyota Techstream) is used to monitor CVT temp so the level is set bang on.
• Climate comfort: If the A/C cycles oddly or the outside temp reads way off, check the ambient sensor behind the grille for debris, and ensure the cabin aspirator port near the dash isn’t blocked by dust.

Common warning signs include hard starts when cold, rich running, high idle, fans running at odd times, A/C not behaving, or the CVT feeling reluctant when cold. Scanning for codes like P0115–P0119 (ECT), P0110–P0114 (IAT), or A/C sensor faults will point to the culprit. With the right diagnosis and a bit of preventive care, the Wish’s temperature sensors help deliver reliable motoring across Aussie and Kiwi conditions.

Popular questions about 2015 Toyota Wish temperature sensors

Where is the engine coolant temperature sensor located on a 2015 Toyota Wish?

It’s threaded into the engine coolant passage on the cylinder head, typically near the thermostat housing. Under the bonnet, follow the upper radiator hose to the engine—look for a two‑pin connector on a small brass or plastic‑bodied sensor in that vicinity.

If access is tight, removing the engine cover helps. Always let the engine cool before unplugging it, and avoid coolant spills around the connector.

Can a faulty temperature sensor cause poor fuel economy or rough idle?

Yes. If the ECT or IAT reports a colder-than-actual temperature, the ECU enriches the mixture, leading to rough idle, sootier exhaust, and higher fuel use. Hot‑start issues and radiator fans behaving oddly are also common hints.

A quick scan for related fault codes and checking live data (coolant and intake temps) against ambient conditions will confirm the diagnosis before replacing parts.

Do the climate-control temperature sensors need regular servicing?

They don’t have scheduled replacement, but they do appreciate a tidy-up. Clear leaves and bugs from the grille area to keep the ambient sensor honest, vacuum dust from the cabin aspirator inlet, and ensure the evaporator drain is clear to prevent icing that can confuse the evaporator sensor.

If the outside temperature reading is obviously wrong or the A/C hunts, a quick inspection and, if needed, sensor replacement restores normal operation.