Parts for your 2009 Toyota Hilux-Temperature sensors

2009 Toyota Hilux temperature sensors – what they do and how to look after them

Based on Toyota’s factory technical literature for the KUN/GGN Hilux series (2005–2015) — including the Engine Control System sections of the Repair Manual for 1KD‑FTV and 2TR‑FE engines and the Electrical Wiring Diagram for Hilux — temperature sensors are definitely fitted and used on the 2009 Hilux. These sources describe the Engine Coolant Temperature (ECT) sensor, Intake Air Temperature (IAT) sensing, fuel temperature input on diesel models, automatic transmission fluid temperature sensing on auto utes, and air‑conditioning temperature sensors. So yes, temperature sensors are relevant to how this Hilux runs and protects itself under the bonnet.

On a 2009 Hilux, temperature sensors are negative‑temperature‑coefficient thermistors that tell the ECUs exactly how hot or cold things are. The ECT sensor is the big one for day‑to‑day driveability — it helps set fuel and timing during warm‑up, controls idle speed, and brings on the radiator fans via the ECU where equipped. Intake air temperature data keeps fuelling tidy as the charge heats up under boost. Diesel variants watch fuel temperature to protect the system and refine injection, and autos use ATF temperature to manage shift quality and torque converter lock‑up. The A/C system also relies on ambient and evaporator temp sensors to stop icing and keep cabin comfort sweet.

They’re not a “replace every X kilometres” item, but they do deserve attention at service time:

• Scan live data after a cold start and at operating temp — look for realistic, steady readings.
• Inspect connectors and looms for corrosion or rub‑throughs, especially near the thermostat housing and intake manifold.
• Keep coolant fresh and correct — poor coolant can cook the ECT sensor and skew readings.
• If the temp gauge is odd, fans run constantly, cold starts are rough, or fuel use spikes, check for DTCs like P0115–P0119 (ECT) or P0110 (IAT) and test the sensor before guessing parts.
• When replacing, use quality coolant‑safe sealant if specified, torque to spec, and bleed the cooling system properly.

A healthy set of temperature sensors helps the 2009 Hilux start cleanly on frosty mornings, tow confidently on hot days, and avoid costly overheating dramas. If any readings don’t make sense, a quick diagnostic beats swapping bits at random every time.

Where is the engine coolant temperature sensor on a 2009 Hilux?
On most 1KD‑FTV diesels it’s threaded into the water outlet/thermostat housing at the front of the engine with a two‑pin connector. On 2TR‑FE petrol models it’s also near the thermostat housing on the cylinder head side. It’s accessible from the top with the engine cover off.

What are common symptoms of a faulty temperature sensor?
Expect hard cold starts, high idle that won’t settle, rich running or black smoke (diesel), poor fuel economy, radiator fans stuck on, or an erratic gauge. Scan tools often show codes like P0115–P0119 (ECT) or P0110 (IAT). Autos may shift harshly if the ATF temp input is out.

Does a 2009 Hilux have more than one temperature sensor?
Yes. Typical sensors include ECT, IAT (location varies by engine), fuel temperature (diesel), ATF temperature (auto transmissions), and A/C ambient/evaporator sensors. Each feeds a different control module to keep the ute running right.