Parts for your 2003 Daihatsu Yrv-Temperature sensors

2003 Daihatsu YRV temperature-sensors

Temperature sensors absolutely are fitted to the 2003 Daihatsu YRV. Factory technical literature for the YRV M200/M201 series lists an engine coolant temperature (ECT) sensor for the K3‑VE and K3‑VET engines, along with an intake air temperature (IAT) thermistor in the air‑metering assembly. These are referenced in the Daihatsu YRV Workshop Manual, Engine Control (EFI) section, and in Autodata specifications for 2003 YRV models. The HVAC system also uses thermistors for evaporator control, and auto‑trans variants incorporate fluid temperature sensing for the transmission ECU.

On this model, the ECT sensor is the primary temperature input the ECU relies on to set fuel, ignition timing, idle speed, and to bring the radiator fan in. A separate dash sender may feed the gauge. The IAT helps the ECU correct for air density, sharpening cold‑start manners and keeping mixtures right on hot Canterbury nor’westers or a humid Brisbane arvo. Turbo YRV trims use the same strategy, with charge temperature carefully monitored upstream of the manifold. Together, these temperature‑sensors keep the YRV starting cleanly, running smoothly, and protecting the alloy head from overheating.

During routine servicing, a quick scan‑tool check of live ECT and IAT readings is worthwhile. From cold, both should read near ambient, as the engine warms, ECT should climb steadily to the thermostat rating. If values jump about or never reach temp, testing the sensor’s resistance against workshop‑manual specs is the next step. Replace any cracked connectors, greened‑up terminals, or leaking sensor O‑rings. Use quality coolant and keep the system bled—air pockets can fool the sensor and trigger the fan late. Common ECT‑related fault codes include P0115–P0119 and P0125.

Watch for:

• Hard cold starts or stalling
• Rich running and poor economy
• Fan running constantly or never
• Temp gauge reading all over
• Check‑engine light and codes

Most ECT sensors are inexpensive and thread out with a deep socket, refit with a new seal and torque lightly. Top up with the correct long‑life antifreeze/antiboil mix, then bleed the cooling system. If in doubt, a workshop can test under the bonnet and replace temperature‑sensors during a normal service. Never open a hot radiator cap.

Where is the engine coolant temperature sensor on a 2003 Daihatsu YRV?

On K3‑VE and K3‑VET engines it’s usually threaded into the thermostat housing or the cylinder head near the upper radiator hose outlet. It’s accessible from the top once the intake ducting is moved aside. Expect a little coolant loss—have a catch tray ready and a new seal on hand.

How often should temperature-sensors be replaced?

There’s no fixed interval. They’re typically replaced when testing shows incorrect readings, related fault codes appear, or connectors are corroded. If the car has overheated or the coolant was contaminated, it’s smart to test and consider replacement. Many owners pre‑emptively fit a new ECT sensor somewhere past 150–200,000 km.

Do I need to bleed the cooling system after changing the ECT sensor?

Yes. Any time the cooling system is opened, bleed it so trapped air doesn’t cause hot spots or false temperature readings. Fill with the specified long‑life coolant mix, run the engine with the heater on, and top up as bubbles purge from the system.