Parts for your 2017 Daihatsu Bego-Temperature sensors

Technical sources confirm that the 2017 Daihatsu Bego (J200-series platform shared with the Daihatsu Terios and Toyota Rush, typically running the 3SZ-VE 1.5-litre engine) is fitted with multiple temperature sensors. The manufacturer workshop manuals for the J200-series Engine Control System describe the Engine Coolant Temperature (ECT) sensor and Intake Air Temperature (IAT) sensor, including their diagnostic steps and expected readings. The Toyota Rush J200 repair literature likewise details on‑vehicle inspection for the coolant temperature sensor and its role in fan control and fuelling. Denso’s engine management training materials further outline how NTC thermistor‑type sensors (as used for ECT/IAT) provide the ECU with temperature data for mixture, ignition timing and fan operation. These sources make it clear that temperature sensors are relevant and used on the 2017 Daihatsu Bego.

2017 Daihatsu Bego temperature sensors—purpose, service and replacement

On a 2017 Daihatsu Bego, temperature sensors quietly keep everything sweet under the bonnet. The big one is the engine coolant temperature (ECT) sensor, which tells the ECU how warm the engine is so it can sort cold‑start enrichment, ignition timing, idle speed and when to kick the radiator fans on. You’ll also find an intake air temperature (IAT) sensor for air‑fuel trimming, plus temperature sensing for the auto transmission fluid and ambient air for climate control on some trims.

When the ECT sensor goes out of whack, the Bego can run rich, idle high, ping under load, or throw the fans on at odd times. The dash gauge may read funny and the check engine light can pop up with codes like P0115–P0119. A quick scan‑tool check is gold: after an overnight sit, the ECT reading should be close to outside ambient, then climb smoothly to operating temp (roughly 85–95°C) as it warms.

There’s no set replacement interval for the ECT sensor, but it’s smart to inspect it during major services and any time the cooling system is opened. Good maintenance looks like this:

• Check the connector and loom for corrosion, brittle insulation or coolant wicking.
• Verify live data with a scan tool, if readings are jumpy or implausible, test resistance off‑car against the workshop chart.
• Use the correct long‑life coolant and bleed air after cooling‑system work—air pockets can cause false hot readings.

Replacing the ECT sensor is a straightforward driveway job if you’re handy with a spanner. Let the engine cool, depressurise the system, and expect a splash of coolant (catch and dispose of it properly). Swap the sensor and sealing washer, torque to the spec in the workshop manual, reconnect the plug, then top up and bleed the cooling system. After a few kilometres, recheck for leaks and confirm the fans cycle normally.

If the Bego is still misbehaving after a new sensor, look at grounds, thermostat operation and the fan relays. A healthy cooling system and accurate sensors keep the little 3SZ‑VE running happily and sipping fuel the way it should.

Popular questions about 2017 Daihatsu Bego temperature sensors

Where is the engine coolant temperature sensor located?
On the 3SZ‑VE, the ECT sensor is typically threaded into the water outlet/thermostat housing area on the cylinder head (intake side). It’s reachable from the top with a deep socket once the engine is cool. Look for a small two‑pin connector.

Do I need to replace the ECT sensor when changing coolant?
No. Coolant changes don’t require a new sensor. Replace the ECT only if it’s faulty, damaged, corroded, or readings are outside spec. Always bleed the system properly after a coolant change to avoid false temperature readings.

Can a bad temperature sensor make the radiator fans run all the time?
Yes. If the ECU sees an implausibly hot signal, it’ll default the fans on to protect the engine. It can also do the opposite—delay fan operation—so don’t ignore odd fan behaviour or a wandering temp gauge.