Geely EC718 2009 Workshop Manual page 753

Engine
After the vehicle started, ECM works in open-loop mode, in which ECM ignores the Pre-Catalytic oxygen sensor signal voltage when
calculating the Air-Fuel ratio. ECM provides an approximate 450mV reference voltage to the Pre-Catalytic oxygen sensor. When
the engine is running, Pre-Catalytic oxygen sensors start heating and begin to generate a 0-0.1 V voltage, which fluctuates. Once
ECM detects that the Pre-Catalytic oxygen sensor voltage exceeds a preset threshold voltage, ECM immediately enters into the
closed-loop mode. ECM uses Pre-Catalytic oxygen sensor signal voltage to determine the Air-Fuel ratio. If the Pre-Catalytic oxygen
sensor voltage is increased to above the reference voltage (tend to 1 V), the mixture is too rich. If the Pre-Catalytic oxygen sensor
the voltage decreased to below the reference voltage (tend to 0 mV), the mixture is too lean.
ECM provides a signal through ECM harness connector EO01 terminal No.10 to Pre-Catalytic oxygen sensor wiring harness
connector EO02 terminal B and an internal low reference voltage through ECM harness connector EO01 terminal No.2 to Pre-
Catalytic oxygen sensor wiring harness connector EO02 terminal No. A.
2. Conditions For Setting DTC and The Fault Location:
DTC
DTC Detection Strategy
Code
P0131
1. Pre-Catalytic Oxygen Sensor
Voltage Too High
2. Pre-Catalytic Oxygen Sensor
Voltage Too Low
P0132
1. Post-Catalytic oxygen sensor
control integral value is over than
upper limit.
2. Post-Catalytic oxygen sensor
control integral value is lower
P0133
than lower limit.
3. Filtered Pre-Catalytic oxygen
sensor signal period is greater
than the specified value.
1. Signal Circuit Open.
2. Oxygen Sensors High-
P0134
Temperature and High
Resistance.
Conditions For Setting The DTC (Control Strategy)
1. Engine Running Longer Than 60 s.
2. Coolant Temperature Less Than 70°C (158 ºF).
3. Oxygen sensor signal is 0.
4. Duration Longer Than 25 s.
1. Engine Running Longer Than 60 s.
2. Coolant temperature is less than 70°C (158 ºF).
3. Pre-Catalytic oxygen sensor signal is short to power
supply, oxygen sensor signal is around 3,200 mV.
4. Duration Longer Than 25 s.
1. Engine Running Longer Than 60 s.
2. Coolant temperature is greater than 70°C (158 ºF).
3. Engine speed range is 1,700-2,350 rpm.
4. Oxygen sensors to the exhaust oxygen concentration
changes responding time longer than the system
preset threshold.
1. Engine Running Longer Than 60 s.
2. Coolant Temperature Less Than 70°C (158 ºF).
3. Duration Longer Than 25 s.
Control System JL4G15-D
EC718/EC718RV EC715/EC715RV 10/2009
2-671
Fault Locations
1. Sensor Circuit
2. Sensor
3. ECM
1. Sensor Circuit
2. Sensor
3. ECM
4. Mixture Too
Rich
5. Mixture Too
Lean
1. Sensor Circuit
2. Sensor
3. ECM