PCM monitors the current from HO2S. If the heater current is below a certain threshold for more than a predetermined time, the PCM sets a P0056 DTC.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Monitor the current through the heater | 1. Poor Connection 2. HO2S(B1/S1) 3. PCM |
Enable Conditions |
•
Engine Running longer than 60 sec.
•
Heater Duty Cycle greater than 40%
•
Max. Duty Cycle - Min. Duty Cycle less than 5% | |
Threshold value |
•
Filtered Heater Current less than threshold value | |
Diagnosis Time |
•
Continuous (More than 2.5 second failure for every 5 second test ) | |
MIL On Condition |
•
3 Driving Cycles |
