DTC Detection Logic

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.

DTC DETECTION CONDITION AND POSSIBLE CAUSES REFERENCE TABLE

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