Engine Temperature Sensor Assembly for Subaru ️

This precision temp sensor reads coolant heat and reports it to the ECU and the dash. It keeps the mixture right, idle stable, and the radiator fan timed correctly. A healthy reading means smooth cold starts, good fuel economy, and long engine life .

Why this part is needed

The ECU uses coolant temperature to set fuel, ignition timing, and fan on/off. It also manages warm‑up enrichment and A/C load. Without accurate data, the engine cannot self‑tune for weather, load, or traffic.

How it works

Inside is an NTC thermistor. The ECU sends a 5V reference; as coolant heats, resistance drops, changing the return voltage. The computer translates this into temperature, drives the gauge, and switches fans. Threaded body seals with a crush washer for leak‑free service.

What happens if it’s broken

Hard cold starts, high idle, rich or lean mix, black smoke, poor MPG, random stalls, fans stuck on/off, overheating risk, and check engine lights (like temp circuit faults). Long term, it can wash cylinders and damage the catalytic converter ⚠️.

Tech notes

Install on a cold engine. Use fresh seal, torque to spec, and bleed air. Always verify 5V reference and ground before replacing.

Compatibility

• Impreza
• Xv
• Forester
• Brz
• Legacy
• Tribeca
• Exiga