Geely EC718 2009 Workshop Manual page 771

Engine
Yes
Diagnostic completed.
Step 8
5. Repair Instructions:
Replace post-catalytic oxygen sensor. Refer to
2.12.7.26 DTC P0171 P0172 P1167 P1171 P2187 P2188
1. DTC Descriptor:
DTC P0171
DTC P0172
DTC P1167
DTC P1171
DTC P2187
DTC P2188
Engine Control Module (ECM) controls the close-loop Air-Fuel ratio Measure system that achieves optimal combination of
performance, fuel economy and emissions control. In the close-loop mode, the engine control module monitors heated oxygen
sensor (HO S) signal voltage and adjusts fuel supply according to the signal. Changes in fuel supply will change the value of long-
2
term and short-term fuel supply adjustment. Short-term fuel supply adjustment will respond to heated oxygen sensor signal voltage
and rapidly change. These changes will fine tune the fuel supply. Long-term fuel supply adjustment will respond to the trend in short-
term fuel supply adjustment. Long-term fuel adjustment adjusts the fuel supply in order to return to the center of the short-term fuel
adjustment value and controls the short-term fuel adjustment. The ideal fuel adjustment value is around 0%. A positive value indicates
that engine control module is increasing fuel supply to compensate the lean Air-Fuel mixture. A negative value indicates that engine
control module is decreasing fuel supply to compensate the rich Air-Fuel mixture.
2.4.7.1 Post-Catalytic Oxygen Sensor
Mixture Too Lean
Mixture Too Rich
Pre-Catalytic Oxygen Indicating Mixture Too Rich During Deceleration
Pre-Catalytic Oxygen Indicating Mixture Too Lean During Acceleration
Mixture Too Lean When idling
Mixture Too Rich When idling
Control System JL4G15-D
Intermittent Fault. Refer to
No
Fault Check
Replacement.
EC718/EC718RV EC715/EC715RV 10/2009
2-689
2.2.7.3 Intermittent