Parts for your 2018 Suzuki Splash-Temperature sensors

2018 Suzuki Splash temperature sensors — purpose, service and replacement

Temperature sensors are absolutely fitted to the 2018 Suzuki Splash. Technical sources including the Suzuki Splash/Ritz Workshop Manual (K10B/K12B Engine Control System), Suzuki Electronic Fuel Injection training notes, and the SAE J1979 OBD‑II standard all specify an Engine Coolant Temperature (ECT) sensor and an Intake Air Temperature (IAT) sensor for closed‑loop fuel control, fan operation, and diagnostics. Suzuki’s parts catalogues for the Splash/Ritz platform also list the ECT sensor as a serviceable item.

On this little Suzuki, temperature sensors do the quiet heavy lifting that keeps things tidy under the bonnet. The ECT sensor feeds the ECU with real‑time coolant temperature so it can trim fuel on cold starts, kick the radiator fan on at the right time, and protect the engine if temps get spicy. The IAT sensor helps fine‑tune fueling as the weather shifts, while many cars in this range also carry an ambient sensor for the climate display and, on autos, a transmission fluid temp sensor for shift and protection strategy.

• Engine Coolant Temperature (ECT): controls fuelling, ignition timing and radiator fan.
• Intake Air Temperature (IAT): helps the ECU correct mixtures as air density changes.
• Ambient temp (HVAC/display): drives outside‑temp readings and A/C behaviour.

When they drift out of spec, drivers may see a temp gauge acting oddly, a fan running at the wrong time, hard cold starts, rough idle, higher fuel use, or a check‑engine light with ECT/IAT codes. Because these sensors are thermistors, there’s no scheduled replacement interval, they’re serviced on condition.

Good servicing practice on a Splash includes a quick visual and scan at each service: check coolant level and quality, look for green crusting at the ECT connector, confirm the fan cuts in and out normally, and use an OBD‑II scan tool to compare live coolant temp to an infrared reading at the thermostat housing. If numbers are way off, test resistance against the workshop manual chart and replace if needed.

Replacement is straightforward but benefits from care. Work on a stone‑cold engine, relieve pressure, and drain a little coolant below sensor height. Unplug the connector, swap the sensor (with new O‑ring/seal), and tighten to the workshop manual torque. Refill with the correct Suzuki‑approved coolant mix, bleed air, then verify for leaks and clear any fault codes. Avoid thread sealants that can insulate the sensor, and always handle the connector gently—broken tabs invite intermittent faults later.

Popular questions about 2018 Suzuki Splash temperature sensors

How often should the Splash’s coolant temperature sensor be replaced?
There’s no fixed kilometre schedule. The ECT is replaced when faulty or when diagnostics show incorrect readings versus actual temperature. Many last well past 150,000 km if the cooling system is kept clean and connectors stay dry.

As part of regular servicing, it’s worth scanning live data, checking for stored codes, and inspecting the plug for corrosion. If symptoms appear—hard cold starts, random fan behaviour, or poor economy—test before replacing.

Can a dodgy temp sensor cause rough idle or high fuel use?
Yes. If the ECT reports the engine as colder than it is, the ECU enriches the mixture, which can bump up fuel consumption and make idle lumpy. Conversely, a hot‑biased reading can cause lean running and hesitation.

A quick comparison of live ECU temperature to an external thermometer at the housing will reveal a sensor that’s telling porkies.

Where is the ECT sensor on the 2018 Splash?
On K‑series Splash engines it’s typically threaded into the coolant passage near the thermostat housing at the cylinder head end. Look for a small two‑pin connector close to the upper radiator hose outlet.

Access is usually from the top with the air cleaner duct out of the way. Always confirm location and torque in the factory manual for the exact engine variant.