On Board Diagnosis Logic

This self-diagnosis has the one trip detection logic.

DTC DETECTING CONDITION AND POSSIBLE CAUSES CHART

DTC No.	Trouble diagnosis name	DTC detecting condition	Possible cause
P1148 1148 (Bank 1)	Closed loop control function	The closed loop control function for bank 1 does not operate even when vehicle is driving in the specified condition.	Harness or connectors [Air fuel ratio (A/F) sensor 1 circuit is open or shorted.] Air fuel ratio (A/F) sensor 1 Air fuel ratio (A/F) sensor 1 heater
P1168 1168 (Bank 2)	Closed loop control function	The closed loop control function for bank 2 does not operate even when vehicle is driving in the specified condition.

NOTE: DTC P1148 or P1168 is displayed with another DTC for air fuel ratio (A/F) sensor 1.

Perform the trouble diagnosis for the corresponding DTC.