Circuit Description

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

For circuit description see Circuit Description under DTCs P0115, P0117 & P0118.

When THW is 95°F (35°C) or more and less than 140°F (60°C), and THA is 19.9°F (-6.7°C) or more when starting engine, and vehicle speed is changing, P0116 will set if THW change is lower than 37.4°F (3°C) from THW when starting engine (2 trip detection logic). DTC will also set if value of engine coolant temperature sensor will not change more than 33.8°F (1°C) even after repeating 6 trips (detection logic) of adjusting speed pattern with THW more than 140°F (60°C) when engine starts.

DTC P0125 will set if THW is less than 19.4°F (-7°C) for 20 minutes or more after starting engine, and engine coolant temperature sensor value is 68°F (20°C) or less (2 trip detection logic). DTC will also set if THW is 19.4°F (-7°C) or more and less than 50°F (10°C) 20 minutes or more after starting engine, and engine coolant temperature sensor value is 68°F (20°C) or less (2 trip detection logic). DTC will also set if THW is 50°F (10°C) or greater for 2 minutes or more after starting engine, and engine coolant temperature sensor value is 86°F (30°C) or less (2 trip detection logic).

For either DTC, check cooling system and engine coolant temperature sensor.