Parts for your 2012 Nissan Pulsar-Temperature sensors

2012 Nissan Pulsar temperature sensors — what they do and when to service them

Temperature sensors are absolutely fitted to the 2012 Nissan Pulsar (B17 sedan and C12 hatch). Nissan’s Factory Service Manual (C12/B17 ESM) confirms an engine coolant temperature (ECT) sensor in the Cooling (CO) and Engine Control (EC) sections, an intake air temperature (IAT) sensor referenced in the EC section and intake system pages, and a transmission fluid temperature sensor within CVT control (TM section) on CVT-equipped models. The ESM wiring diagrams (PG/EC) also show these sensors feeding the ECM and cluster.

On this Pulsar, the ECT sensor tells the engine computer how warm the engine is, so it can set the right fuel mix, idle speed, ignition timing, and switch the radiator fans. It also drives the dash temperature display logic. If it’s reading wrong, the car can run rich, feel doughy, or switch the fans at the wrong time.

The IAT sensor measures the temperature of the air coming in through the intake. On many Pulsar variants it’s integrated into the MAF sensor, helping the ECM adjust fuelling and spark to suit Aussie/Kiwi climate swings. CVT models also monitor transmission fluid temperature to protect the ’box and adjust shift strategy.

These sensors aren’t regular “replace every X km” items, but they do benefit from attention during servicing. Under the bonnet, check connectors and harnesses for corrosion, brittle insulation, or oil/coolant wicking into plugs. Keeping the cooling system healthy—fresh coolant at the interval shown in Nissan’s maintenance schedule—helps the ECT sensor live a long life and keeps the readings stable.

Common tip-offs a temp sensor needs love include:

• Hard cold starts, high idle, rough running, or poor fuel economy
• Cooling fans running constantly or not at all
• Temp gauge behaving oddly, or the A/C cutting in and out strangely
• ECM fault codes like P0115–P0119 or P0125 (ECT), and P0110–P0113 (IAT)

Replacing the ECT sensor is a straightforward job for a competent home mechanic: let the engine cool fully, relieve pressure, drain a little coolant, unplug the connector, and swap the sensor and seal. Refill with the correct Nissan-spec coolant and bleed air per the ESM. For IAT, if it’s part of the MAF, replacing the MAF assembly is usually the fix, if it’s a separate probe in the intake duct, it’s a simple unplug-and-swap. For CVT temp issues, testing is external but the sensor is internal—leave repairs to a transmission specialist.

A quick scan for codes, a visual once-over of the plugs, and sticking to the coolant service interval will keep the Pulsar’s temp readings spot-on and driving manners tidy.

Popular questions about 2012 Nissan Pulsar temperature sensors

Where is the engine coolant temperature (ECT) sensor located?

On most 2012 Pulsar engines it’s threaded into the thermostat housing or cylinder head, near the upper radiator hose outlet. It’s a two-pin sensor you can see with the intake snorkel out of the way. The exact spot is shown in the Nissan ESM Cooling (CO) and Engine Control (EC) sections for the specific engine code.

Is the intake air temperature (IAT) sensor separate from the MAF?

On many Pulsar variants the IAT is built into the MAF sensor on the intake duct, so you replace the MAF to fix a failed IAT. Some trims use a standalone IAT probe further downstream in the air tube. A quick visual under the bonnet or a check of the EC section in the ESM will confirm which layout your car has.

What fault codes point to a bad temperature sensor?

Typical ECT-related codes include P0115, P0116, P0117, P0118 and P0125. IAT-related codes include P0110, P0112 and P0113. Before replacing parts, rule out wiring or connector issues and verify coolant level and condition, as these can trigger the same codes.