DTC Detection Logic

2019 Infiniti Q70 3.7 Luxe, AWDSECTION DTC Detection Logic
WARNING: This page is about a different variant/trim than selected.
NOTE: DTC P1148 or P1168 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 (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-B2

[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.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.