Parts for your 2007 Subaru Forester-Temperature sensors

2007 Subaru Forester Temperature Sensors

Temperature sensors are absolutely fitted to the 2007 Subaru Forester. The Subaru Factory Service Manual for the SG/MY2007 models details several monitored temperature inputs, notably the engine coolant temperature (ECT) sensor with DTCs P0115–P0119 and P0125, and the intake air temperature (IAT) sensor (often integrated into the MAF on EJ253 engines) with DTCs P0110–P0114. Subaru’s parts catalogue also lists the ECT sensor (commonly 22630AA161, superseded by 22630AA280) and a transmission fluid temperature sensor in the 4EAT control system—clear technical confirmation that temperature sensors are integral to this vehicle.

On this Forester, temperature sensors look after a stack of critical jobs. The ECT sensor tells the ECU how hot the engine is, so it can set cold-start enrichment, adjust ignition timing, run the radiator fans, and manage idle speed. The IAT sensor helps the ECU fine-tune fuelling for air density changes—handy from a frosty Dunedin morning to a steamy Darwin arvo. If it’s an automatic, the transmission fluid temperature sensor influences shift timing and line pressure for smooth gearbox behaviour. Models with automatic climate control also use an ambient temp sensor to guide cabin comfort.

They’re small, but when a temperature sensor goes out of whack, the Forester can drink more petrol, idle rough, crank longer when cold, or kick the cooling fans on at odd times. The dash light might pop up with codes like P0115–P0119 (ECT), P0125 (insufficient coolant temp), P0128 (thermostat performance), or P0110–P0114 (IAT).

There’s no set replacement interval—these sensors are “replace-on-condition” items. As part of routine servicing, it’s smart to:

• Scan for fault codes and live data, especially after cooling system work.
• Keep coolant fresh and at the right spec, poor coolant can shorten sensor life.
• Inspect connectors and grounds for corrosion, oil, or brittle wiring under the bonnet.
• For MAF-integrated IAT, keep the air filter clean and the MAF spotless with proper MAF cleaner (never touch the element).

When replacing the ECT sensor, only do it stone cold, relieve system pressure, and top up/bleed coolant afterward. Use the correct OEM-spec sensor, a new seal or washer if applicable, and tighten to the service manual torque. If the AT temp sensor is flagged, testing is typically done via the transmission control diagnostics, replacement may require transmission pan/valve body access, so many owners leave that to a pro.

Popular questions

Where is the coolant temperature sensor on a 2007 Forester?
On EJ25-powered 2007 Forester models, the ECT sensor is threaded into the coolant crossover passage near the front/top of the engine, close to the thermostat housing and alternator, under the intake manifold area. Access improves with the engine cold and some hose and connector clearance.

Turbo variants position it on the coolant pipework as well, but the exact angle and harness routing can differ. A quick look at the top-front of the engine usually spots the two-pin connector on the brass/steel sensor body.

Which fault codes point to a bad temperature sensor?
Common ECT-related codes are P0115–P0119 and P0125, while P0128 often indicates a thermostat issue that can mimic sensor faults. For intake temperature, look for P0110–P0114. Transmission temp faults may trigger an AT TEMP light and gearbox codes, along with harsh or protective shifting.

Always confirm with live data—if the coolant temp reading is wildly cold or hot compared to reality, the sensor or wiring likely needs attention.

Do temperature sensors need maintenance or calibration?
No calibration is required, the ECU handles interpretation. Preventative care is mostly about environment: correct coolant type and change intervals, tidy wiring, clean connectors, and a healthy air filter/MAF for IAT accuracy.

If symptoms appear or codes set, test first—many issues trace back to connectors or grounds rather than the sensor itself. Replace with quality OEM-spec parts when needed.