Parts for your 2021 Suzuki Splash-Temperature sensors

2021 Suzuki Splash temperature-sensors: what they do and how to look after them

Temperature sensors are absolutely used on the 2021 Suzuki Splash. Suzuki service literature for the K10B/K12B engines fitted to Splash models describes the Engine Coolant Temperature (ECT) sensor and Intake Air Temperature (IAT) sensor as key inputs to the engine control module. Suzuki’s electronic parts catalogues list a water temperature sensor for these engines, and mainstream repair data providers (e.g., Autodata/AllData) show diagnostic specs and live-data values for ECT and IAT on Splash variants. On top of that, OBD‑II/SAE J1979 requires a coolant temperature parameter, which is derived from an ECT sensor—so any 2021‑compliant petrol Splash will have one.

On this Splash, temperature-sensors feed the brain of the car with real-time heat info. The ECT sensor tells the ECU how warm the engine is, so fuelling, ignition timing, idle speed and radiator fan control stay on point. The IAT sensor helps fine-tune mixture by reporting the temperature of air entering the intake. Many cars also have an ambient temp sensor for the dash/HVAC, and some trims include a cabin temp sensor for climate control. When they work right, cold starts are clean, the fan cuts in when it should, and fuel economy stays tidy.

They’re not a routine “replace every X km” item, but they do age. Poor readings can cause hard starts, rich running, high fuel use, lazy heater performance, or the cooling fan going full tilt. A quick scan with an OBD2 tool will show live ECT/IAT numbers—handy for catching issues early during a service.

• Common signs something’s off: rough cold start, black exhaust smoke, temp gauge acting weird, cooling fan stuck on or never coming on, and a check engine light with codes like P0115–P0119 (ECT) or P0110–P0114 (IAT).
• Basic care: keep coolant fresh and at the correct spec, fix any leaks promptly, and ensure connectors aren’t green with corrosion or oil-soaked.

Replacement is straightforward with the right care. Always start with a cold engine. For an ECT sensor, expect a small coolant loss—have a drain pan ready, and top up with the correct premix. Swap the sensor and O‑ring/seal, snug it to the torque in the Suzuki workshop data (don’t overtighten), reconnect the plug, then bleed the cooling system so there’s no air under the bonnet to cause hot spots. For an IAT that’s built into the airbox or intake tube, it’s usually a clip-and-twist affair—just make sure the intake ducting is reseated and airtight.

Quality matters: use OEM or a trusted brand so the resistance curve matches what the ECU expects. If diagnostics are needed, a multimeter and the service manual specs let a tech compare resistance at known temperatures (for many NTC sensors, higher resistance when cold, lower when hot). Done right, sensor care is quick, cost-effective, and keeps the Splash running sweet as.

FAQs

Where is the coolant temperature sensor on a 2021 Suzuki Splash?
On K10B/K12B engines it’s typically threaded into the thermostat housing or the cylinder head near the coolant outlet. Owners will spot a small two‑pin connector on a stubby sensor body in that area. Access is usually from the top with the engine cover off.

What are the symptoms of a bad temperature sensor on a Splash?
Expect cold-start hassles, rich running, poor fuel economy, a temp gauge that’s jumpy or dead, and cooling fans behaving oddly. The ECU may log codes like P0115–P0119 (ECT) or P0110–P0114 (IAT). Live data that shows implausible readings (e.g., 120°C on a stone-cold engine) is a giveaway.

Do you need to bleed the cooling system after replacing the ECT sensor?
Yes. Even a small air pocket can cause overheating or erratic heater performance. Top up with the correct coolant mix, run the engine with the heater on, and follow Suzuki’s bleed steps until the level stabilises and the radiator fan cycles normally.