Sym RV 250i Service Manual page 59

4. Fuel Injection System
O Sensor
2
O Sensor
2
Rich ← 14.7 → Lean
Function
O Sensor measures the proportion of oxygen in the exhaust gas, sending signals to ECU which adjusts
2
the air-fuel ratio by changing the fuel injection time. If the proportion of oxygen is too low, it means the rich
air-fuel mixture with higher HC & CO concentration in the exhaust gas. If the proportion of oxygen is too
high, it means the lean air-fuel mixture with higher temperature and higher NOx concentration.
O Sensor outputs feedback signal to ECU which keeps the air-fuel mixture near the stoichometric ratio
1.
2
approximately 14.6 and forms the closed loop control system.
When the air-fuel mixture is near the stoichometic ratio, CO / HC / NOx are converted most efficiently.
2.
O Sensor heater resistance: 6.7 ~ 10.5 Ω
3.
2
O Sensor amendment in the voltage value: between 100 ~ 900 mV
4.
2
4-10
To this chapter contents
Power relay
ECU
Battery
3
2
1
O Sensor
2
4
1.
Ceramics tube
2.
Electrode
3.
Emissions
4.
Atmosphere