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Home >> Toyota >> 2004 >> Highlander Limited, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 891 (Engine Control System (Diagnostic Codes & Symptom Tests)) >> DTC/Circuit Diagnosis >> DTC P0117, P0118: ECT Sensor >> Component Description

Component Description

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

The engine coolant temperature sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the ECM. The modified signal returns to the ECM as the engine coolant temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.

Fig 1: Identifying Engine Coolant Temperature Sensor, Gasket And Terminals
G08690477Courtesy of NISSAN NORTH AMERICA, INC.
REFERENCE DATA

Engine coolant temperature °C (°F)] Voltage(1) (V) Resistance (kΩ)
-10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
(1) These data are reference values and are measured between ECM terminal 73 (Engine coolant temperature sensor) and ground.
Fig 2: Engine Coolant Temperature Sensor Resistance Graph
G08690478Courtesy of NISSAN NORTH AMERICA, INC.
CAUTION: Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in damage to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.