The PCM tests rear HO2S signal level during the time the lambda target point is being shifted to rich to determine rear HO2S signal stuck. The PCM sets DTC P2270 if rear HO2S signal is below the predetermined threshold while target lambda point is being shifted to the predetermined value. If the same error code is set in the next driving cycle, the PCM illuminates the MIL.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Electrical Monitoring | 1. Poor Connector Connection 2. Defected Downstream O2 Sensor |
Enable Conditions |
•
No fuel cut off
•
No Full load
•
No catalyst over heating protection
•
Battery voltage higher than 11V and lower than 16V | |
Threshold Value |
•
Downstream O2 Sensor Voltage less than 0.75 when lambda set point is 0.8 | |
Diagnostic Time |
•
7 sec. after lambda set point shift to corresponding side | |
MIL ON Condition |
•
2 Driving Cycle |
