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Home >> Lexus >> 2007 >> RX 400h AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 191 (Engine Control System (2UZ-FE)) >> SFI System >> DTC P0115 Engine Coolant Temperature Circuit: 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: 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 2007 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

A thermistor is built into the Engine Coolant Temperature (ECT) sensor and changes the resistance value according to the engine coolant temperature.

The structure of the sensor and connection to the ECM is the same as the Intake Air Temperature (IAT) sensor.

HINT:

If the ECM detects the DTC P0115, P0117 or P0118, it operates the fail-safe function in which the ECT is assumed to be 80°C (176°F).

DTC TROUBLE DETECTION CONDITION

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

HINT:

Confirm the ECT using the intelligent tester. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / COOLANT TEMP.

MALFUNCTION CHART

Temperature Displayed Malfunction
-40°C (-40°F) Open circuit
140°C (284°F) or more Short circuit