A heated oxygen sensor (HO2S) indicating lean at the end of a test is trying to correct for an over-rich condition. This DTC sets when the fuel control system no longer detects switching for a calibrated amount of time.
Item | Detecting Condition | Possible Cause | |
DTC Strategy | Case1 |
•
Characteristic line strong shift to lean | 1. Poor connection 2. S1 3. Blocking of intake system 4. Fuel leakage in injector 5. Improper fuel pressure |
Case2 |
•
Characteristic line middle shift to lean | ||
Enable Conditions | Case1 |
•
Sensor pump current valid (same as the conditions of P0133)
•
Downstream O2 sensor operative readiness detected (same as the conditions of P0133)
•
Active test not activated
•
Cat.purge after fuel cut off not active
•
Engine speed > 580rpm
•
Mass air flow < 83g/sec
•
300°C < Exhaust gas temperature model < 800°C
•
Stable driving condition: abs(rpm - filtered rpm) < 500rppm & abs(air mass - filtered air mass) < 0.4g/rev & abs(lambda - filtered lambda) < 15% | |
Case2 |
•
No fuel cut off
•
No full load
•
No catalyst overheating protection
•
11V < Battery voltage < 16V | ||
Threshold Value | Case1 |
•
[ Upstream lambda (lean) > 1.1V and Downstream O2 signal (rich) > 0.75V and Lambda controller in limit ] = 50% When above conditions are fulfilled. mass air flow is integrated. Malfunction is detected when the accumulated mass air flow reaches 300g. | |
Case2 |
•
Lambda value (when lambda setpoint=0.80) > 0.9 | ||
Diagnostic Time | Case1 |
•
5..100 sec (depending on intake air mass) | |
Case2 |
•
10 sec after lambda set point shift to corresponding side | ||
MIL ON Condition |
•
2 Driving Cycles | ||
※ S1 : upstream oxygen sensor / S2 : downstream oxygen sensor
