P2251: O2 Sensor Reference Ground Circuit/Open (Bank 1 Sensor 1): DTC Detecting Condition

DTC DETECTING CONDITION CHART

Item	Detecting Condition	Possible Cause
DTC Strategy	Open circuit check of front HO2S circuit	Contact resistance in connectors Open or Short to ground in HO2S circuit Front HO2S
Enable Conditions	No Pump current malfunction
Threshold Value	Front HO2S signal during fuel cut-off > 4.9V
Diagnostic Time	Below 1300 sec.
Mil On Condition	2 Driving Cycles