Parts for your 2014 Subaru Impreza-Temperature sensors

2014 Subaru Impreza temperature sensors — purpose, care and when to replace

Based on Subaru’s Factory Service Manual for the 2014 Impreza (GJ/GP), the Subaru Technical Information System (STIS) and the Subaru electronic parts catalogue, temperature sensors are absolutely fitted and relevant on the 2014 Subaru Impreza. The engine coolant temperature (ECT) sensor, intake air temperature (IAT) sensing within the MAF assembly, ambient temperature for HVAC/instrument display, and transmission fluid temperature (for CVT models) all feed critical data to the control modules.

These sensors do more than drive a gauge. The ECT sensor lets the engine computer know how hot the coolant is so it can fine‑tune cold‑start fuelling, idle speed and ignition timing, switch the radiator fans on and off, and protect the engine if things get too warm under the bonnet. The IAT sensor helps adjust fuelling and timing based on the density of incoming air — especially important on hot Aussie and Kiwi days or cool early mornings. On Lineartronic CVT models, a fluid temperature sensor informs shift logic and line pressure, helping the transmission stay smooth and protecting it from overheating.

There’s no scheduled replacement interval for temperature sensors on the 2014 Impreza, but they do age. Tell‑tales include hard cold starts, a high idle that won’t settle, poor fuel economy, cooling fans running constantly, the temp gauge behaving oddly, or a check engine light with codes like P0115–P0119 or IAT‑related faults. A quick scan of live data comparing ECT/IAT to ambient temperature after an overnight sit is a great first check — they should read closely to outside temp before start‑up.

When replacement is needed, go with quality OEM‑spec parts, follow torque specs from the service manual, and top up with the correct Subaru Super Coolant premix if the ECT sensor is removed. Bleed the cooling system properly to avoid air pockets. Don’t slather sealant on sensors unless the manual specifies it, most use an O‑ring or washer to seal. If your IAT is part of the MAF, resist poking the element — use a dedicated MAF‑safe cleaner only. CVT fluid temperature sensing is built into the transmission’s control hardware and isn’t a routine service item, if diagnostics point to it, address wiring/connectors first before assuming the sensor itself has failed.

• Inspect connectors and harness routing at every major service.
• Fix coolant or intake leaks promptly — they can skew sensor readings.
• Use a scan tool to verify temps after repairs and during road tests.

Popular questions about 2014 Subaru Impreza temperature sensors

How do you spot a failing coolant temperature sensor on a 2014 Impreza?
Common signs are hard cold starts, rough running until warm, poor fuel economy and cooling fans that run at odd times. After an overnight park, read ECT with a scan tool, it should be close to outside temperature. If the reading is way off, or DTCs P0115–P0119 are stored, the sensor, wiring or connector needs further checks.

Is the intake air temperature sensor separate or built into the MAF?
On most 2014 Impreza FB20 engines, the IAT sensing element is integrated into the mass air flow (MAF) sensor housing. If IAT readings are suspect, inspect and, if needed, clean the MAF carefully with MAF‑safe cleaner. Replacement typically means swapping the MAF assembly rather than a separate IAT sensor.

Do CVT models have a transmission fluid temperature sensor that needs servicing?
Yes, CVT models use fluid temperature sensing for shift strategy and protection, but it isn’t a regular service item. If the car logs CVT temperature or performance codes, check fluid condition, cooling lines and electrical connections first. Sensor faults are uncommon compared with wiring or heat‑related issues.