Geely EC715 2009, Workshop Manual

Page: 142 / 2181

Data Stream Name
Ignition Switch
"ON"
Idle Speed
2,500 rpm
When
Diagnosis Description
Group 1 Oxygen
Sensor Voltage 1
(Pre-Catalytic
Oxygen Sensor)
0.4 V 0.1-0.7 V 0.1-0.7 V
Under normal operating conditions, HO
2
S output
is 0.1-0.9V voltage. ECM receives this voltage
signal and measures whether the Air-Fuel ratio is
lean or rich. If ECM input signal voltage is lower
than 0.45V, the Air-Fuel ratio is lean; if the input
signal voltage is above 0.45V, the Air-Fuel ratio
is rich. In the closed-loop control, ECM
continuously detects HO
2
S output signal to
reduce or increase the fuel injection control pulse
width to adjust.
Group 1 Oxygen
Sensor Voltage 2
(Post-Catalytic
Oxygen Sensor)
0.6 V 0.7 V 0.7 V
The Post-Catalytic oxygen sensor is installed
after the catalytic converter or in exhaust pipe.
The Post-Catalytic oxygen sensor output voltage
is between 0 V-1V. Use the Post-Catalytic oxygen
sensor signal to detect the catalytic converter
efficiency. If the conversion efficiency of catalytic
converters is good, the Post-Catalytic oxygen
sensor signal is stable. If the catalytic converter
is aging, toxic or Misfire and so on, the conversion
efficiency of catalytic converters will decrease.
The Post-Catalytic oxygen sensor signal will be
similar to the Pre-Catalytic oxygen sensor signal.
Group 1 Oxygen
Sensor Integral Value
(Long-Term
Adjustments)
1.0 1.0 1.0
The long-term fuel adjustment value is stored in
ECM memory, because it is calculated as part of
the basic injection duration. It will not be deleted
when ignition switch is OFF. It affects the closed-
loop control and open-loop control injection
duration. ECM uses the short-term adjustment
value to modify the long-term fuel adjustment
value. It can not respond quickly to the instant
changes. It only changes when ECM decides to
use the short-term fuel adjustment value to adjust
the long-term fuel adjustment value. Like the
short-term fuel value adjustment, when the long-
term value is 0%, it indicates that the basic
injection duration does not need adjustment.
Positive percentage indicates the fuel injection
increase; while a negative percentage indicates
the fuel injection decrease. The long-term value
is for engine to control the entire range of injection
duration. It is divided into two categories; long-
term idle and long-term under load. When is
engine speed is lower than 920 rpm and the air
volume is 24kg/h, it monitors long-term idle.
Because the relatively small amount of intake air,
2-60 Control System JL4G18-D Engine
EC718/EC718RV EC715/EC715RV 10/2009