Parts for your 2005 Daihatsu Yrv-Temperature sensors

2005 Daihatsu YRV Temperature Sensors — What They Do and How to Look After Them

Temperature sensors are absolutely fitted to the 2005 Daihatsu YRV. The Daihatsu YRV (M200/M201, K3‑VE/K3‑VET) Workshop Manual and EFI Diagnostics detail the engine coolant temperature (ECT) sensor for the ECU and gauge, plus an intake air temperature (IAT) sensor (integrated with the MAF/MAP depending on variant). The Automatic Transmission diagnostics list an ATF temperature sensor on auto models, and the Air‑Conditioning manual covers evaporator and ambient temperature sensors. These are also reflected in the factory OBD‑II fault code set (e.g., P0115 for ECT, P0110 for IAT). Technical sources: Daihatsu YRV Service Manual (Engine/EFI), A/T Diagnostic Manual, and A/C System Manual for M2xx series.

On the 2005 YRV, temperature sensors quietly run the show. The ECT sensor tells the ECU how hot the engine is so it can sort cold‑start enrichment, ignition timing, idle speed, and trigger the radiator fans. It also feeds the dash gauge, giving the driver a fair idea of coolant temperature. The IAT sensor helps the ECU trim fuelling and timing as the air coming in gets hotter or cooler, keeping the engine smooth and efficient. Auto models also watch transmission fluid temperature to protect the gearbox, while the A/C system uses temp sensors to prevent evaporator freeze‑up and keep cabin temps steady.

They’re not a routine “replace by kilometres” part, but a bit of care goes a long way. As part of scheduled servicing, it’s smart to:

• Scan live data to confirm ECT and IAT readings make sense from cold start to operating temp.
• Inspect connectors for green corrosion, brittle clips, and oil/coolant wicking into the loom.
• Maintain coolant quality and level as per the manual — fresh, correct long‑life coolant helps the ECT read accurately and avoids scale around the sensor tip.
• Clean the IAT (if exposed) using proper MAF cleaner only, never use brake or carb cleaner.

Common clues a temp sensor is crook include hard cold starts, rich running, stalling at lights, the radiator fan stuck on, dodgy gauge behaviour, or fault codes like P0115/P0117/P0118 (ECT) and P0110 (IAT). If replacement is needed, let the engine cool right down. For the ECT, catch and top up coolant, swap the sealing washer or O‑ring, and nip it up to workshop spec — don’t overtighten. Bleed the cooling system to avoid airlocks, clear codes, and recheck live data. For IAT that’s built into a MAF/MAP unit, replacement usually means changing the whole sensor body. On automatic models, the ATF temp sensor is internal to the transmission and diagnosed via scan data, service the fluid and address wiring issues first.

Looked after properly, these little sensors keep the YRV feeling lively, economical, and happy on Aussie and Kiwi roads.

• Where is the coolant temperature sensor on a 2005 YRV?
• Does the YRV’s IAT sensor come separate or built into another sensor?
• Can a bad ECT sensor make the radiator fan run constantly?

Where is the coolant temperature sensor on a 2005 YRV?
On K3‑VE/K3‑VET engines it’s typically near the thermostat housing or on the cylinder head by the upper radiator hose outlet. Look for a two‑pin connector. There may also be a separate sender for the dash gauge depending on trim.

Does the YRV’s IAT sensor come separate or built into another sensor?
It varies by variant. Many YRVs have the IAT integrated with the MAF or MAP assembly. If readings are off, cleaning with proper MAF cleaner can help, otherwise the whole unit is usually replaced.

Can a bad ECT sensor make the radiator fan run constantly?
Yes. If the ECU sees implausible coolant temperature (open or shorted circuit), it can default the fan to run as a fail‑safe. It can also cause rich running, rough idle, and poor fuel economy.