Parts for your 2008 Toyota Aurion-Temperature sensors

2008 Toyota Aurion Temperature Sensors

Temperature sensors are absolutely fitted to the 2008 Toyota Aurion (GSV40, 2GR‑FE V6). Factory technical documentation—including the Toyota Aurion Electrical Wiring Diagram (EWD), the 2GR‑FE Engine Repair Manual, and Aisin U660E automatic transaxle service information—details multiple temperature inputs used by the engine, transmission and HVAC systems. These include the engine coolant temperature (ECT) sensor, intake air temperature (IAT, incorporated in the mass airflow sensor on this model), ambient air temperature sensor for the climate control, and transmission fluid temperature sensors.

On this Aurion, the temperature sensors do more than just feed the dash gauge. The ECT tells the engine ECU how warm the motor is so it can sort cold-start enrichment, ignition timing, VVT‑i control and radiator fan operation. The IAT helps the ECU trim fuel and spark based on air density. The ambient sensor helps the A/C and climate control behave properly. The trans fluid temperature input lets the U660E manage shift timing and line pressure to protect the gearbox and keep shifts smooth when cold or under load.

• Common signs a temperature sensor is playing up: hard cold starts, hunting idle, soggy performance, poor fuel economy, radiator fans stuck on or never coming on, erratic temp gauge, or a check engine light (typical codes include P0115–P0119, P0128 for coolant temp, P0711/P0712/P0713 for trans temp).
• Good servicing habits: keep coolant fresh (Toyota Super Long Life Coolant—first change at up to 160,000 km or 10 years, then every 80,000 km or 5 years), check connectors for corrosion or broken locks, and inspect wiring looms where they flex or run near hot components.

Replacement is straightforward for most sensors, provided the engine is cool. The ECT is threaded into the coolant outlet housing on the front bank, expect a small coolant loss when swapping. Use the correct sealing washer or sealant as specified, snug to the service manual torque, then bleed the cooling system to avoid air locks. The IAT is part of the MAF—if the IAT fails, the MAF assembly is typically replaced. The ambient sensor sits behind the grille, if readings look off, check that it isn’t blocked or heat-soaked. Transmission fluid temperature issues should be confirmed with scan-tool live data before diving into the pan.

Diagnosis is best done with a scan tool: after an overnight soak, ECT should read close to ambient. A resistance check of the thermistor against the manual’s temperature–ohms chart is a handy double-check. Quality OEM or reputable aftermarket parts keep the Aurion happy for the long haul, with no dramas.

Popular questions

Where is the engine coolant temperature sensor on a 2008 Aurion?
It’s mounted in the coolant outlet housing on the front bank of the 2GR‑FE V6, near the thermostat and upper radiator hose area. Access usually involves removing the engine cover and intake ducting. Expect a small coolant spill, top up with Toyota SLLC and bleed the system afterwards.

Do temperature sensors need regular replacement on an Aurion?
They aren’t a scheduled replacement item. They’re replaced when testing shows a fault or when symptoms point to bad data. Keeping coolant fresh, connectors clean and wiring intact helps sensors last. Use a scan tool to compare cold ECT against ambient and review live data before deciding.

Can a faulty temperature sensor cause poor fuel economy?
Yes. If the ECT or IAT reports the wrong temperature, the ECU may over-fuel, retard timing or run the radiator fans at the wrong time. That can mean rough cold starts, excessive fuel use and lazy performance. Fault codes like P0128 or P0117/P0118 are common clues.