If the HO2S signal voltage is fixed at rich status, then feedback control is no longer possible, the PCM sets DTC P2196.
Item | Detecting Condition | Possible Cause | |
DTC Strategy |
•
Characteristic Monitoring | 1. Poor Connector Connection 2. Defected Upstream O2 Sensor | |
Enable Condition | Case 1 |
•
Sensor Pump current valid
•
Downstream O2 Sensor operative readiness detected(Downstream O2 sensor voltage lower than 0.25V or higher than 0.56V & Downstream O2 sensor max heating finished)
•
Active Test not activated
•
Catalyst purge after fuel cut off not active
•
Engine speed higher than 600 RPM
•
Mass air flow less than 83 g/sec.
•
Exhaust gas Temp. higher than 572℉(300℃) and lower than 1472℉(800℃)
•
Stable driving condition | |
Case 2 |
•
No Fuel Cut Off
•
No Full Load
•
No catalyst overheating protection
•
Battery voltage higher than 11V and lower than 16V | ||
Threshold Value | Case 1 |
•
Upstream Lambda(rich) below 0.9 and Downstream O2 signal voltage below 0.2V(lean) and lambda controller in limit(-30%) | |
Case 2 |
•
Lambda value below 1.05 when lambda setpoint is 1.15 | ||
Diagnostic Time | Case 1 |
•
5 to 100 sec. depending on intake air mass | |
Case 2 |
•
10 sec. after lambda setpoint shift to corresponding side | ||
MIL ON Condition |
•
2 Driving Cycle | ||
