Diagnostic Aids
WARNING: This page is about a different car, the 2000 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
After confirming DTC P0116, use scan tool to access CURRENT DATA to confirm engine coolant temperature. If ECT sensor value displayed on scan tool is always -40°F (-40°C), ECT sensor circuit may be open. If ECT sensor value displayed on scan tool is always 284°F (140°C), ECT sensor circuit may be shorted. Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected.