Parts for your 2007 Daihatsu Bego-Temperature sensors

2007 Daihatsu Bego temperature sensors: what they do and how to look after them

Per the Daihatsu Bego/Toyota Rush J200E service manual and Toyota’s 3SZ‑VE engine repair literature, the 2007 Bego is absolutely fitted with multiple temperature sensors. These include the engine coolant temperature (ECT) sensor, an intake air temperature (IAT) sensor integrated with the airflow meter, and—on automatic models—an automatic transmission fluid (ATF) temperature sensor. Variants with air‑conditioning may also carry ambient and evaporator temperature sensors. In short, temperature sensors are integral to this model.

On the 3SZ‑VE, the ECT sensor is the brains’ best mate, telling the ECU how warm the engine is so it can trim fuel, ignition timing and idle speed, run the radiator fans at the right time, and feed the dash gauge. The IAT helps the ECU judge air density for cleaner burn and better economy. Auto transmissions use fluid temperature to shape shift timing and line pressure, keeping changes smooth. Climate control uses ambient and evaporator temps to stop the system freezing up and to keep cabin comfort sweet as.

While these sensors aren’t regular “consumables”, they deserve a quick health check during servicing. A scan tool should show the ECT matching outside temperature on a cold start, then climbing smoothly to roughly 85–95°C at operating temp with no sudden spikes. Inspect connectors for corrosion, brittle wiring and coolant seepage around the sensor boss. Use the correct Toyota/Daihatsu Super Long Life Coolant and keep the cooling system clean to protect the sensor tip. Poor earths can also skew readings, so a tidy electrical system helps.

• Common signs a sensor’s due for replacement: hard cold starts, rough idle, rich smell or black smoke, thirsty fuel use, radiator fans running flat‑out or never engaging, random temp gauge swings, A/C cutting in and out, harsh shifting on autos, and engine lights with codes like P0115–P0119 (ECT), P0125, P2185, or P0110 (IAT).

When replacement’s on the cards, work on a cold engine. Depressurise the system, drain a little coolant below the sensor level, then swap the sensor using the correct deep socket and a fresh sealing washer or O‑ring. Tighten to the workshop manual spec, refill with the right coolant mix, bleed air, clear any fault codes and recheck live data. IAT faults often mean replacing the airflow meter as a unit. ATF temperature sensors sit inside the transmission and are generally tackled only when diagnostics point squarely at them.

• Where is the engine coolant temperature (ECT) sensor on a 2007 Daihatsu Bego?
  On the 3SZ‑VE engine, it’s typically threaded into the thermostat housing/outlet neck near the upper radiator hose, under the front of the intake manifold. It uses a two‑pin plug and can be reached from under the bonnet with a deep socket once the connector is off.
• What should a healthy ECT reading look like on a scan tool?
  Cold starts should read close to ambient (within a few degrees). As the engine warms, it should climb smoothly to around 85–95°C, with radiator fans cycling on and off as expected. A fixed reading at –40°C or 130°C usually indicates a sensor or wiring fault.
• Can a dodgy temperature sensor cause overheating?
  It can contribute by preventing the fans from kicking in or by skewing fuelling, but true overheating often points to a thermostat, radiator, water pump or coolant issue. It’s best practice to test the sensor data and pressure‑check the cooling system together.