2004 Nissan-Datsun Sentra SE-RFACTORY OEM SERVICE PROCEDURE

Component Description

WARNING: This page is about a different car, the 2005 Nissan 350Z. However, it is still accessible from the selected car via links, so may be relevant.

The engine coolant temperature sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the ECM. The modified signal returns to the ECM as the engine coolant temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.

Fig 1: ECT Sensor Components
G02401409Courtesy of NISSAN MOTOR CO., U.S.A.

< Reference data>Β 

ENGINE COOLANT TEMPERATURE VOLTAGE AND RESISTANCE

Engine coolant temperature Β°C (Β°F) Voltage(1) V Resistance kΞ©
-10 (14) 4.4 7.0-11.4
20 (68) 3.5 2.1-2.9
50 (122) 2.2 0.68-1.00
90 (194) 0.9 0.236-0.260
(1) This data is reference values and is measured between ECM terminal 73 (Engine coolant temperature sensor) and ground.
Fig 2: Resistance & Temperature Graph
G02401410Courtesy of NISSAN MOTOR CO., U.S.A.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.