Parts for your 2015 Toyota Wish-Temperature sensors

2015 Toyota Wish temperature-sensors — what they do and when to service them

Temperature-sensors are absolutely fitted to the 2015 Toyota Wish. Toyota’s service literature for the ZGE2# series (New Car Features, Electrical Wiring Diagram, and Repair Manual) details multiple thermistors, including the engine coolant temperature (ECT) sensor, intake air temperature (IAT) sensor, ambient air sensor for the A/C, and an evaporator temperature sensor. The CVT likewise relies on a transmission fluid temperature input. These are also reflected in standard OBD‑II data items and fault codes (for example, P0115–P0119 for ECT, P0110–P0113 for IAT), consistent with Toyota diagnostics and SAE J1979. Denso’s thermistor specs used by Toyota align with the resistance‑versus‑temperature behaviour these systems expect.

On a 2015 Wish, temperature-sensors quietly keep everything sweet. The ECT sensor tells the engine ECU how hot the coolant is, so it can sort cold starts, fuel trims, ignition timing, idle speed and when to kick the radiator fans on. The IAT sensor helps with air‑density calculations for smoother response and better economy. The A/C sensors (ambient and evaporator) protect the system from icing and help the climate control hold a steady cabin temp. The CVT’s temperature input allows the transmission control to manage line pressure, shift feel and protective strategies when things get too hot or too cold.

When these sensors go out of whack, the Wish can be harder to start when cold, run rich, feel doughy, use more fuel, or run the fans when it really doesn’t need to. Climate control may cycle oddly or blow warm. The CVT can default to a protective mode and feel reluctant.

There’s no fixed replacement interval for temperature-sensors, they’re serviced by condition. As part of routine servicing, it’s smart to:

• Scan live data and compare ECT/IAT readings to actual ambient when cold (they should be close).
• Check connectors and earths for corrosion, coolant weep and brittle loom sections.
• Keep coolant fresh (Toyota SLLC service intervals apply) so sensors aren’t sitting in contaminated fluid.
• Verify fan cut‑in temps and thermostat operation.

If an ECT or IAT fails testing, replacement is straightforward: let the engine cool, disconnect the battery, drain enough coolant if required, swap the sensor with a quality part, renew the seal, torque correctly, then bleed the cooling system and verify with live data. The CVT fluid temperature sensor is typically integrated within the transmission’s internal harness or valve body assembly, so that job’s best left to a transmission specialist. Always clear codes and road‑test, watching temps and fan command on a scan tool.

• What temperature-sensors does a 2015 Toyota Wish have?
  It commonly includes engine coolant temperature (ECT), intake air temperature (IAT), ambient air temperature and an A/C evaporator sensor, plus a CVT fluid temperature input. These are documented in Toyota’s NCF, EWD and RM materials for the ZGE2# Wish and appear in OBD‑II data.
• How can someone tell if the coolant temperature sensor is faulty?
  Look for hard cold starts, rich running, poor economy, high or hunting idle, fans running constantly, or a temp gauge that behaves oddly. A scan tool showing implausible ECT (e.g., stuck at −40°C or 130°C) when the engine is cold is a giveaway.
• Do they need to service the CVT temperature sensor separately?
  Not usually. It’s typically built into the transmission’s internal harness/valve body. Focus on correct CVT fluid, change intervals and cooling health, if the sensor faults, a specialist will diagnose and replace the internal component as required.