Parts for your 2016 Subaru Forester-Temperature sensors

2016 Subaru Forester temperature-sensors — what they do and how to look after them

Temperature-sensors are absolutely fitted to the 2016 Subaru Forester and they’re critical to how the vehicle runs. Technical references that confirm this include the 2016 Forester factory service manual and wiring diagrams available via Subaru’s Technical Information System, which document the Engine Coolant Temperature (ECT) sensor, Intake Air Temperature (IAT) sensor, Ambient Air Temperature sensor, and the Continuously Variable Transmission (CVT) fluid temperature sensor. Related diagnostic trouble codes used by Subaru for this model year include ECT (P0117/P0118), IAT (P0112/P0113), ambient air temp (P0072/P0073) and CVT fluid temperature (P0711/P0713). HVAC documentation also covers evaporator temperature sensing for the air-con system.

• Engine Coolant Temperature (ECT) sensor
• Intake Air Temperature (IAT) sensor
• Ambient (outside) Air Temperature sensor
• CVT fluid temperature sensor (internal to transmission)
• Evaporator temperature sensor (HVAC)

On a 2016 Forester, these temperature-sensors let the engine and transmission computers make smart decisions. The ECT sensor guides cold-start fuelling, ignition timing, idle speed and radiator fan control. The IAT helps fine‑tune fuelling and knock control. The ambient sensor feeds the climate control and dash display, while the CVT temperature input protects the transmission by adjusting line pressure and strategy as fluid temperature changes. The evaporator sensor stops the air‑con freezing up and keeps cabin temps stable. Without accurate readings, the car can run rich or lean, chew through fuel, turn the fans on at the wrong time, or even throw the CVT into a protective limp mode.

There’s no scheduled replacement interval for these sensors, but they’re worth a look during regular servicing. A quick scan-tool check is gold: when the engine is stone cold, ECT and IAT should read close to outside temperature. After warm‑up, ECT should stabilise at normal operating temperature, and the radiator fans should cycle predictably. Inspect connectors and looms for green crust, broken clips or oil/coolant contamination. Healthy coolant and good grounds help sensors report accurately.

Replacement is straightforward for most external sensors: the ECT usually sits near the thermostat housing—swap it on a cold engine, catch and refill coolant, then bleed the system and verify operation with a scan tool. The IAT (often integrated with the MAF on non‑turbo models) can sometimes be restored with proper MAF‑safe cleaner if it’s just dirty. The ambient sensor lives up front and is easy to replace if it’s been knocked about. The CVT temperature sensor is internal, that one’s a specialist job involving transmission work. Always use quality OEM‑spec parts and tighten to the factory torque spec from the service manual.

Common clues a temp sensor is playing up include hard cold starts, rough idle, poor economy, radiator fans that run constantly, outside temperature readings that are obviously wrong, the A/C cycling oddly, or a CVT overheat warning on a steep climb. If any of that crops up, a quick diagnostic with live data usually points straight to the culprit.

Popular question: Where is the engine coolant temperature sensor on a 2016 Forester?

It’s mounted on the engine near the coolant outlet/thermostat housing area. Access is typically from under the bonnet with basic hand tools. Always work on a cold engine and follow the factory bleeding procedure after any coolant loss.

Popular question: Do temperature-sensors need regular servicing?

They’re not a scheduled replacement item. As part of routine servicing, it’s smart to check live data, inspect connectors, ensure coolant is fresh and correct, and keep the intake tract and MAF/IAT clean. Replace any sensor that’s out of spec or flagged by a fault code.

Popular question: Can a bad temperature sensor trigger fans or CVT warnings?

Yes. An ECT fault can command radiator fans to run constantly or cause rich fuelling. A dodgy CVT fluid temperature reading can put the transmission into a protective strategy and light the warning lamp. Scanning for codes like P0117/P0118 (ECT) or P0711 (CVT temp) helps confirm the issue quickly.