Parts for your 1993 Nissan Primera-Temperature sensors

1993 Nissan Primera temperature sensors: what they do and how to look after them

Temperature sensors are absolutely fitted to the 1993 Nissan Primera (P10). Technical references that document this include the Nissan Primera P10 Factory Service Manual (EF&,EC and Cooling System sections), the Instrumentation section for the dash sender, and period Nissan CONSULT diagnostic information (which lists an Engine Coolant Temperature fault as Code 13). General guides such as the Haynes Primera 1990–1999 manual also note the coolant temp sensor/sender arrangement and the intake air temperature sensing used for fuel control. Across GA16DE and SR20DE petrol engines—and the CD20 diesel—temperature sensing is part of normal operation.

On this Primera, temperature sensors do a few vital jobs. The engine coolant temperature (ECT) sensor feeds the ECU so it can adjust fuelling, ignition timing, idle speed, and cold-start enrichment. A separate one-wire sender runs the dash gauge so the driver can see what’s happening under the bonnet. There’s also intake air temperature (IAT) measurement—often integrated in the mass airflow sensor on these Nissans—to fine-tune mixtures as air density changes. Autos add transmission fluid temperature sensing, and higher-spec climate control systems use ambient and evaporator temp sensors. Without these bits, the car would be hard to start, run rich, chew through fuel, and the radiator fans wouldn’t kick in at the right time.

Servicing is straightforward. These sensors aren’t a scheduled replacement item, but they’re worth checking at every service if there are signs of trouble. Common clues include hard cold starts, lumpy idle, poor economy, the gauge reading weirdly, or the fans running at odd times. Under the bonnet, the ECT sensor and the separate gauge sender sit near the thermostat housing, the two-pin plug is for the ECU, the single wire is for the gauge. Test resistance against temperature with a multimeter and compare to factory charts, or pull codes via the ECU/CONSULT. If replacing, work on a cool engine, drop the coolant level below the sensor, swap the part with a new sealing washer where specified, and tighten to the factory spec—don’t overdo it. Refill with the correct coolant mix and bleed the system so there are no airlocks. For IAT/MAF issues, use proper MAF cleaner only—no touching the sensing wire. Kept clean and connected, these sensors will go the distance and keep the Primera running sweet as.

• Quick checks: inspect connectors for corrosion, cracked housings, or loose pins.
• If the dash gauge works but the ECU shows Code 13, focus on the two-pin ECT sensor and its wiring.
• After any coolant work, confirm the fans cycle correctly and the upper hose warms evenly.

FAQs

Where is the coolant temperature sensor on a 1993 Nissan Primera?
It’s mounted near the thermostat housing on the engine. You’ll typically see two senders there: a two-pin sensor for the ECU and a single-wire sender for the dash gauge. Access is under the bonnet, front side of the engine, and it’s easiest to reach with the engine cool.

What are the signs the temperature sensor has failed?
Look for hard cold starts, black exhaust smoke, rough idle, poor fuel economy, radiator fans behaving strangely, or a gauge that reads too low or too high. The ECU may store a fault (often ECT Code 13 on Nissan OBD1). Always confirm with resistance tests and wiring checks before replacing.

Can it be driven with a faulty coolant temperature sensor?
It might run, but it’s not a great idea. The ECU can default to a limp strategy that over-fuels, which wastes petrol and can foul plugs or dilute oil. There’s also a risk of overheating if the fans don’t switch correctly. Best to diagnose and fix before regular driving.