Parts for your 2000 Daihatsu Gran move-Temperature sensors

2000 Daihatsu Gran Move temperature sensors — what they do and how to look after them

Temperature sensors are absolutely fitted to the 2000 Daihatsu Gran Move (also sold as the Pyzar). Daihatsu’s factory workshop manual for the Pyzar/Gran Move EFI system specifies an Engine Coolant Temperature (ECT, often labelled THW) sensor feeding the engine control unit, and an Intake Air Temperature (IAT) sensor for mixture correction. The service wiring diagrams also show the ECT signal being used to command radiator fan operation via the ECU, and the parts catalogue lists a dedicated water temperature sensor/sender for the model’s 1.5‑litre fuel‑injected engine. These technical sources confirm temperature sensors are relevant and used on this vehicle.

On this Gran Move, the ECT sensor under the bonnet tells the ECU how warm the engine is. That data sets cold‑start enrichment, idle speed, ignition timing, and when to kick the cooling fans on. The IAT sensor lets the ECU adjust fuelling for hot or cold intake air, keeping drivability tidy across seasons and altitudes. Many examples also have a separate sender for the dash gauge, so the gauge and ECU aren’t fighting over one signal.

When these sensors drift off, owners may notice hard cold starts, lumpy idle, rich running, poor fuel economy, cooling fans that run at odd times, or a check‑engine light with common OBD‑II codes like P0115–P0119. The Daihatsu literature provides resistance‑to‑temperature charts for quick diagnosis, a basic multimeter check against a cup of hot and cool water can spot a dud thermistor.

As part of routine servicing on a 2000 Gran Move, it’s smart to:

• Inspect the ECT connector for green corrosion and brittle terminals, clean with proper electrical cleaner.
• Keep coolant fresh and at the right spec, neglected coolant can attack the sensor tip and housing.
• If replacing the ECT, work on a cold engine, catch a little coolant, swap the sensor with a new sealing washer, then refill and bleed air from the system.
• For IAT housed in the airbox or airflow meter, clean gently with MAF‑safe cleaner—no harsh sprays or poking the element.
• Use quality OEM‑equivalent parts, cheap sensors can skew readings and waste fuel over thousands of kilometres.

There’s no fixed change interval, it’s condition‑based. That said, on a 20‑plus‑year‑old Gran Move, pre‑emptive replacement of a suspect ECT can be cheap insurance against over‑fuelling and fan control headaches.

Popular questions about 2000 Daihatsu Gran Move temperature sensors

Where is the coolant temperature sensor located?

On most 2000 Gran Move engines, the ECT screws into the thermostat housing or the cylinder head near the top radiator hose outlet. It has a two‑pin connector. A separate single‑pin sender (if fitted) nearby may feed only the dash gauge.

If visibility is tight, a small mirror and torch help spot the hex body and connector under the intake plumbing.

Do the ECU and dash gauge share the same sensor?

Many Gran Move variants use two devices: a two‑wire ECT for the ECU and a separate one‑wire sender for the cluster. That means the gauge can read “normal” while the ECU sensor is lazy—or vice versa—so diagnosing with scan data or a multimeter is best practice.

Can the ECT sensor be tested at home?

Yes. With the connector unplugged, measure resistance across the two ECT pins and compare against typical thermistor behaviour: high resistance when cold, dropping smoothly as the sensor warms in hot water. Any open circuit, wild jumps, or values far off spec suggest replacement.