FixVault

DTC Detection Logic

NOTE: DTC P1148 is displayed with DTC for A/F sensor 1.
When the DTC is detected, perform the trouble diagnosis of DTC corresponding to A/F sensor 1.
DTC No. Trouble diagnosis name
(Trouble diagnosis content)
DTC detecting condition Possible cause
P1148 CLOSED LOOP-B1
(Closed loop control function)
The closed loop control function does not operate even when vehicle is being driven in the specified condition.
  • Harness or connectors

    (A/F sensor 1 circuit is open or shorted.)

  • A/F sensor 1
  • A/F sensor 1 heater