Parts for your 2007 Nissan Serena-Temperature sensors

2007 Nissan Serena temperature sensors — what they do and how to look after them

Yes, the 2007 Nissan Serena absolutely uses temperature sensors. The C25-series Factory Service Manual (FSM) for the Serena outlines multiple temperature inputs across the vehicle: the engine coolant temperature (ECT) sensor in the Engine Control (EC) section, intake air temperature (IAT) sensor within the air flow meter, automatic air conditioner sensors (ambient and in-vehicle) in the HAC section, and a transmission fluid temperature sensor in the CVT control system (TM section). These are standard OBD‑II monitored items and relate to diagnostic codes such as P0115–P0119 (ECT circuit) and P0710 (transmission fluid temperature), per Nissan’s service literature and SAE J1979 practices.

On a 2007-nissan-serena, temperature sensors feed the ECU and control units info they need to manage fuelling, ignition timing, idle speed, cooling fans, CVT shift strategy, air‑con performance, and what’s shown on the dash gauge. They’re typically negative temperature coefficient (NTC) thermistors—tough little units, but they can drift with age, heat cycling, or coolant contamination.

• Engine Coolant Temperature (ECT): Governs cold starts, warm‑up enrichment, radiator fan operation, and gauge.
• Intake Air Temperature (IAT): Trims fuelling and spark based on air density.
• CVT Fluid Temperature: Protects the trans and manages shift/ratio strategy and limp mode.
• HVAC Ambient/In‑Vehicle Sensors: Optimise cabin temperature control and compressor logic.

They’re not a scheduled-replacement item, but they should be checked any time there’s cooling system work, poor fuel economy, odd fan behaviour, or a MIL on. A scan tool that shows live data is gold—compare ECT and IAT against a cold ambient reading after the Serena’s been parked overnight, they should be close. Resistance checks against the FSM chart can confirm a lazy sensor. Also inspect connectors, earths, and the condition of the coolant, old or contaminated coolant can shorten sensor life.

• Common symptoms of a dodgy temp sensor: hard cold starts, rich running, high idle, fans stuck on or never engaging, erratic gauge, CVT going protective, weak A/C performance, or DTCs like P0116/P0117/P0118 and P0710.

Replacing the ECT on the MR20DE is straightforward for a competent home mechanic. It’s typically near the thermostat housing. Work on a cold engine, disconnect the battery, catch and reuse/replace coolant as required, and avoid overtightening—follow the torque spec in the Nissan FSM. Use quality OEM or equivalent sensors, avoid generic thread sealants unless the part instructions specify it (many use an O‑ring or pre‑applied sealant).

As part of regular servicing, have the shop verify temperature readings, check for stored codes, and confirm the cooling system is bled properly after any work. Sticking with the correct Nissan long‑life coolant and replacing it at the recommended interval helps keep those sensors healthy for the long haul across Aussie and Kiwi conditions.

Popular questions about 2007 Nissan Serena temperature sensors

Q: Where is the engine coolant temperature sensor on a 2007 Serena?

On MR20DE-equipped C25 models, the ECT sensor is mounted in the coolant passage near the thermostat housing on the engine. Access is from the top with some intake ducting moved aside. Always confirm by matching the new sensor to the one on the engine and cross‑checking in the Nissan FSM.

Q: What faults or codes point to a bad temperature sensor?

For the coolant sensor, expect P0115–P0119 series codes and symptoms like hard cold starts, rich running, or fans misbehaving. Transmission temp issues may log P0710 and force the CVT into a protective mode. Live data that doesn’t track ambient on a cold start is another strong clue.

Q: Do temperature sensors need regular replacement?

No set interval. They’re replaced on condition—when data, tests, or symptoms indicate a fault. During coolant service, it’s smart to check the sensor readings and connector condition. Using the correct coolant and maintaining clean electrical connections helps them last.