KS Motorcycles K-LIGHT125, Maintenance Manual

Page: 264 / 278

18.2.7 Oxygen Sensor
18.2.7.1 Working Principle of Oxygen Sensor
Oxygen sensor can be used to detect the oxygen content in the waste gas of engine exhaust pipe for internal
fuel closed loop control of ECU, thus maintaining engine combustion at the most reasonable state of air and fuel
ratio (14.7).
18.2.7.2 Appearance of Oxygen Sensor
18.2.7.3 Technical Parameters

Partially thick limit of air-fuel ratio:
＞
750mVDC

Partially thin limit of air-fuel ratio:
＜
120 mVDC

The resistance of heater is: 9.6±1.5Ω (measured at 21°C)

Operating temperature range: 260-850°C
18.2.7.4 Fault Determination
1. Conduct fault diagnosis with a diagnostic instrument and judge the fault type
2. Check whether pins fall off
3. Check the voltage between sensor line and signal ground with a multimeter: Standard When the engine
temperature is 80 degrees and the idle speed or constant speed is 3000 revolutions, 4000 revolutions or 5000
revolutions, the duration is more than 2 minutes. Measure whether the voltage at both ends changes between 0-1V
constantly. Otherwise, the sensor fails.
4.Determination of oxygen sensor heating: measure the resistance between two pins (two white lines) of sensor
heating rod with multimeter; Standard: 9.6±1.5Ω (measured at 21
℃ )
The measurement diagram is as follows:
V
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