Engine - Coolant Temperature Sensor/Switch: Testing and Inspection

Water Thermosensor Testing:

1. Disconnect water thermosensor connector.
2. Check resistance across sensor terminals and compare to chart below:

COOLANT TEMP. RESISTANCE (K OHMS)

-20°C (-4°F) 14.6 - 17.8
20°C (68°F) 2.2 - 2.7
40°C (104°F) 1.0 - 1.3
60°C (140°F) 0.50 - 0.65
80°C (176°F) 0.29 - 0.35

3. If not as specified, replace sensor.

Water thermosensor input voltage can be checked at ECU terminal 2E. With ignition switch "ON" and engine at operating temperature, terminal voltage should be approximately 0.3 - 0.6V.