LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2002 >> Q45 >> Repair and Diagnosis >> External Pages >> Different car >> Section 216 (Engine Control System) >> DTC P0117, P0118: ECT Sensor >> Component Description
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Component Description

WARNING: This page is about a different car, the 2004 Infiniti Q45. 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.

< Reference data > 

Fig 1: Reference data (1 Of 2)
G00760438Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Reference data (1 Of 2)
G00760439Courtesy of NISSAN MOTOR CO., U.S.A.
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.