Engine Coolant Temperature (ECT) Switch: Inspection

WARNING: This page is about a different car, the 2003 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.

REMOVE ENGINE UNDER COVER
DRAIN ENGINE COOLANT FROM RADIATOR
HINT:

It is not necessary to drain out all coolant
REMOVE ENGINE COOLANT TEMPERATURE SWITCH
1. Disconnect the connector.
2. Remove the engine coolant temperature switch.
3. Remove the O-ring from the switch.
Fig 1: Removing Engine Coolant Temperature Switch Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT ENGINE COOLANT TEMPERATURE SWITCH
1. Using an ohmmeter, check that no continuity exists between the terminals when the coolant temperature is above 100 °C (212 °F).
  If continuity exists, replace the switch.
2. Using an ohmmeter, check that continuity exists between the terminals when the coolant temperature is below 91 °C (196 °F).
If there no continuity exists, replace the switch.

Fig 2: Inspecting Engine Coolant Temperature Switch
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSTALL ENGINE COOLANT TEMPERATURE SWITCH
1. Install the new O-ring to the switch.
2. Install the engine coolant temperature switch.
  Torque: 7.4 N.m (75 kgf.cm, 65 in.lbf)
FILL WITH ENGINE COOLANT TO RADIATOR
INSTALL ENGINE UNDER COVER