Parts for your 2018 Nissan Serena-Temperature sensors

2018 Nissan Serena temperature sensors — what they do and how to look after them

Temperature sensors absolutely are used on the 2018 Nissan Serena (C27). Technical references including the Nissan C27 Electronic Service Manual (ESM, 2018 editions: Engine Control, HVAC, Transmission, and e-POWER sections) and Nissan’s parts catalogue list multiple temperature sensors fitted from factory. These include the engine coolant temperature (ECT) sensor, intake air temperature (IAT, typically integrated with the MAF), ambient air temperature (front bumper area), A/C evaporator and in-car thermistors, and the CVT fluid temperature sensor for Xtronic models. e-POWER variants also have high-voltage battery temperature sensors within the pack. So, temperature sensors are not only relevant — they’re central to how the Serena drives, cools, and protects itself.

Across petrol/CVT and e-POWER models, these sensors help the ECM, TCM, HVAC, and hybrid systems make smart decisions in real time. They steer cold-start fuelling and ignition timing, command the radiator fans, set CVT shift and protection strategies, regulate cabin comfort, and (on e-POWER) manage battery health and output. If a sensor drifts or fails, the Serena can run rich, idle high, kick the fans on constantly, soften its A/C, or drop the CVT into a protective mode.

• ECT: tracks engine warmth for fuelling, fans, and the dash gauge.
• IAT: fine-tunes mixture based on incoming air temperature.
• Ambient/evaporator/in-car: keeps climate control stable and fog-free.
• CVT fluid temperature: safeguards the transmission under load or heat.
• e-POWER battery sensors: protect the HV pack and regulate performance.

There’s no scheduled replacement interval for these sensors. Good servicing practice in Australia and New Zealand is to check live data with a scan tool during routine services, confirm cold-start ECT aligns with ambient, and inspect connectors and looms under the bonnet for corrosion or rub-through. Keep coolant fresh and at the correct spec to help the ECT read consistently, and ensure the front ambient sensor isn’t obstructed by debris or aftermarket accessories. Clean a combined MAF/IAT only with proper MAF cleaner — don’t touch the thermistor.

Replace a sensor when diagnostics back up the symptoms: hard cold starts, poor economy, high idle, weak or erratic A/C, fans that won’t switch off, or CVT limp behaviour. Common DTCs include P0115–P0119 (ECT), P0110 (IAT), P0070–P0073 (ambient), and P0711 (CVT fluid temperature). Use quality or genuine parts and follow the ESM for procedures — especially bleeding after ECT replacement. CVT temperature sensors can be integrated in the internal harness, so that job is best for a transmission specialist. For e-POWER, any high-voltage battery temperature concerns must be handled by a certified EV technician.

Where is the engine coolant temperature sensor on a 2018 Serena?

On most MR20DD petrol models it’s threaded into the thermostat housing or cylinder head near the upper radiator hose, accessible from the top once the engine cover is off. e-POWER models use a different engine layout (as a generator) and the sensor position varies