The downstream heated oxygen sensor (HO2S) is forced rich and lean and monitored by the PCM. This DTC sets when the PCM does not detect the output of the HO2S in a calibrated amount of time.
Item | Detecting Condition | Possible Cause | |
Case 1 | DTC Strategy |
•
No signal activity | 1. Poor connection 2. Short to Power in signal circuit 3. HO2S(S2) 4. PCM 5. Exhaust leaks |
Enable Conditions |
•
Battery voltage greater than 10.7 V
•
Lambda = 1.1 for 9 sec. | ||
Threshold Value |
•
Downstream O2S voltage less than 0.65 V | ||
Case 2 | DTC Strategy |
•
Oscillation check : Test condition is checked at every 500 sec after oscillation check is performed | |
Enable Conditions |
•
Downstream O2S voltage greater than 0.65 V for 100 sec.
•
Fuel system status = Closed loop
•
Engine speed greater than 1120 rpm and less than 3000 rpm
•
Engine load greater than 20 % and less than 83 %
•
Mass airflow greater than 20 kg/h
•
EGT around downstream O2S greater than 700 ℃(1292 °F) or O2S heater voltage greater than 9.2 V or Downstream O2S voltage greater than 0.5 | ||
Threshold Value |
•
If All secondary conditions met then Fuel system open loop control Lambda = 1.1 for 9 sec. | ||
Diagnosis Time |
•
10 sec. | ||
MIL On Condition |
•
2 Driving Cycles | ||
