Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection

1999 Lexus RX 300 AWD V6-3.0L (1MZ-FE)SECTION Testing and Inspection



1. DRAIN ENGINE COOLANT
2. REMOVE ECT SENSOR
a. Disconnect the ECT sensor connector.
b. Using a 19 mm deep socket wrench, remove the ECT sensor and gasket.




3. INSPECT ECT SENSOR
Using an ohmmeter, measure the resistance between the terminals.
Resistance: Refer to the graph
If the resistance is not as specified, replace the ECT sensor.

4. REINSTALL ECT SENSOR
a. Install a new gasket to the ECT sensor.
b. Using a 19 mm deep socket, install the ECT sensor.
Torque: 20 Nm (200 kg.cm, 14 ft.lb)
c. Connect the ECT sensor connector.

5. REFILL WITH ENGINE COOLANT


RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

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

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

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

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