Engine Coolant Temperature (ECT) Sensor Inspection

Warm up sender gauge (2). Make sure its resistance is decreased with increase of its temperature.

ECT sender gauge specifications 

at 50°C (122°F):  136 - 216 Ω

at 120°C (248°F)  16.4 - 19.4 Ω

Fig 1: Checking Engine Coolant Temperature (ECT) Sensor

Courtesy of SUZUKI OF AMERICA CORP.