Parts for your 2001 Daihatsu Yrv-Temperature sensors

2001 Daihatsu YRV Temperature Sensors — What They Do and How to Look After Them

Temperature sensors are absolutely fitted to the 2001 Daihatsu YRV and are central to how it runs. The K3-VE (1.3L) and K3-VET (1.3L turbo) engines use an engine coolant temperature (ECT) sensor and an intake air temperature (IAT) sensor to feed the ECU with live data. That info steers fuelling, ignition timing, fan control and cold-start behaviour.

• Technical sources referenced: Daihatsu YRV Workshop/Service Manual for K3-VE/K3-VET EFI systems (ECT and IAT sensor identification, specs and ECU pins).
• Daihatsu diagnostic trouble codes applicable to YRV: P0110–P0114 (IAT circuit) and P0115–P0119 (ECT circuit), confirming the sensors are monitored by the ECU.
• Australian/NZ service data (Autodata/Autoinfo) for 2001 YRV: shows ECT on the thermostat housing/cylinder head and IAT in the air intake tract, with test values and replacement guidance.

On a 2001 Daihatsu YRV, the temperature sensors quietly handle a heap of important jobs. The ECT tracks coolant temp so the ECU can sort cold starts, warm-up enrichment, fan operation and knock control. The IAT helps the ECU fine-tune fuelling as air density shifts with ambient conditions. When either goes out of spec, the YRV can chew more fuel, idle rough, feel doughy off the line, kick the fan in at odd times, or light the check engine lamp.

They’re not scheduled “replace-at-X-kilometres” items, but they are worth checking any time there’s cooling system work, a MIL light, or odd temperature readings. A quick scan-tool sweep is gold: compare ECT to actual engine temp on cold start (both should read ambient) and ensure the rise is smooth as the engine warms. For IAT, compare to ambient, big outliers suggest a lazy sensor or wiring issue.

If the ECT is being replaced, expect it near the thermostat housing or on the head. Let the engine cool, relieve pressure, and catch the coolant. Swap the sensor using the correct deep socket, fit a new seal if applicable, and don’t overtighten—use factory torque. Refill with the correct coolant mix and bleed the system so there’s no airlock. On turbo K3-VET models, tidy hose routing and heat shielding matter—keep wiring off hot hardware.

For the IAT, it may be integrated in the air flow meter or sit in the intake tube. Make sure the connector is clean and terminals are snug. If it’s a standalone sensor, it’s usually a simple unplug-and-swap. Any time sensors are handled, check earths and harness condition—crusty plugs cause more dramas than the sensors themselves.

Good habits for Aussie and Kiwi conditions:

• Use quality coolant, keep the mix right, and renew per service schedule—overheated engines cook sensors.
• Fix cooling system leaks early and keep the radiator clear of debris.
• When diagnosing, always rule out wiring faults before throwing parts at it.

Where is the engine coolant temperature sensor on a 2001 Daihatsu YRV?

It’s typically threaded into the thermostat housing or the cylinder head, with a two-pin connector. On some K3-VE/K3-VET layouts, you’ll spot it right near the top radiator hose outlet. Access is usually straightforward with a deep socket, but give yourself room by moving the intake duct if needed.

What are the symptoms of a failing temperature sensor on the YRV?

Common signs include hard cold starts, high idle that lingers, rich running and poor economy, the radiator fan cycling oddly, or a check engine light with codes like P0115–P0119 (ECT) or P0110–P0114 (IAT). A scan-tool reading that doesn’t match ambient on a cold engine is a giveaway.

Does the ECU need programming after replacing an ECT or IAT sensor?

No special programming is normally required. Clear any stored fault codes, start the engine, and let it reach operating temperature so the ECU can relearn trims. If issues persist, recheck wiring, grounds and connector fitment, then verify live data again.