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Home >> Lexus >> 2013 >> IS 250C Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 11 (Engine Control System (Diagnostic Codes (P0010-P014F)) >> SFI System >> DTC P0115: Engine Coolant Temperature Circuit Malfunction; DTC P0117: Engine Coolant Temperature Circuit Low Input; DTC P0118: Engine Coolant Temperature Circuit High Input >> Description
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DTC P0115: Engine Coolant Temperature Circuit Malfunction; DTC P0117: Engine Coolant Temperature Circuit Low Input; DTC P0118: Engine Coolant Temperature Circuit High Input: Description

WARNING: This page is about a different car, the 2013 Lexus IS 350C. However, it is still accessible from the selected car via links, so may be relevant.

A thermistor, whose resistance value varies according to the engine coolant temperature, is built into the engine coolant temperature sensor.

The structure of the sensor and its connection to the ECM are similar to those of the intake air temperature sensor.

HINT: 

When any of DTCs P0115, P0117 or P0118 are set, the ECM enters fail-safe mode. During fail-safe mode, the engine coolant temperature is estimated to be 80°C (176°F) by the ECM. Fail-safe mode continues until a pass condition is detected.

DTC No. DTC Detection Condition Trouble Area
P0115 Open or short in engine coolant temperature sensor circuit for 0.5 seconds
(1 trip detection logic)
  • Open or short in engine coolant temperature sensor circuit
  • Engine coolant temperature sensor
  • ECM
P0117 Short in engine coolant temperature sensor circuit for 0.5 seconds
(1 trip detection logic)
  • Short in engine coolant temperature sensor circuit
  • Engine coolant temperature sensor
  • ECM
P0118 Open in engine coolant temperature sensor circuit for 0.5 seconds
(1 trip detection logic)
  • Open in engine coolant temperature sensor circuit
  • Engine coolant temperature sensor
  • ECM

HINT: 

When any of these DTCs are set, check the engine coolant temperature by entering the following menus on the Techstream: Powertrain / Engine / Data List / Coolant Temp.

Temperature Displayed Malfunction
-40°C (-40°F) Open circuit
Higher than 135°C (275°F) Short circuit