Geely EC718 2009 Workshop Manual page 198

2-116 Control System JL4G18-D
Yes
Diagnostic completed.
Step 16
5. Repair Instructions:
Replace the pre-catalytic oxygen sensor. Refer to
2.2.7.22 DTC P0136 P0137 P0138 P0140 P2270 P2271
1. DTC Descriptor:
DTC P0136
DTC P0137
DTC P0138
DTC P0140
DTC P2270
DTC P2271
After the vehicle is started, the control module works in the open-loop mode and ignores heated oxygen sensor signal voltage when
calculating air-fuel ratio. The control module provides approximately 450mV reference voltage to the heated oxygen sensor. When
the engine starts running, the heated oxygen sensor will be heated and begin to generate a 0-0.1V voltage. This voltage fluctuates.
Once the control module detects that the heated oxygen sensor voltage exceeds a threshold voltage, it will immediately enter into
the closed-loop mode. Control module determines the air-fuel ratio using the received heated oxygen sensor voltage signal. If the
heated oxygen sensor voltage increases to over the reference voltage (tend to 1V), it indicates that the air fuel mixture is too rich.
If the heated oxygen sensor voltage decreases to below the reference voltage (tend to 0mV), it indicates that the air fuel mixture is
too lean.
•
ECM provides a signal through ECM harness connector EN01 terminal No.29 to post-catalytic oxygen sensor wiring harness
connector EN03 terminal No.4.
• ECM provides a low reference voltage through ECM harness connector EN01 terminal No.39 to pre-catalytic oxygen sensor
wiring harness connector EN03 terminal No.3.
2. Conditions For Setting DTC and The Fault Location:
DTC Code
P0136
Short to Ground When Cold
P0137
EC718/EC718RV EC715/EC715RV 10/2009
2.4.7.2 Pre-Catalytic Oxygen Sensor
Post-Catalytic Oxygen Sensor Unreasonable
Post-Catalytic Oxygen Sensor Circuit Voltage Too Low
Post-Catalytic Oxygen Sensor Circuit Voltage Too High
Post-Catalytic Oxygen Sensor Circuit Malfunction
Post-Catalytic Oxygen Sensor Aging (Tool Lean)
Post-Catalytic Oxygen Sensor Aging (Too Rich)
DTC Detection Strategy
Intermittent Fault. Refer to
No
Fault Check
Conditions For Setting The DTC
(Control Strategy)
1. Post-Catalytic oxygen sensor
voltage is less than 0.06 V.
2. Post-Catalytic oxygen sensor
reaches the normal working
temperature.
2.2.7.3 Intermittent
Replacement.
Fault Locations
1. Sensor Circuit
2. Sensor
3. Mixture Too Rich
4. Mixture Too Lean
Engine