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Home >> Infiniti >> 2021 >> QX80 Premium Select, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (4 Of 5) >> Engine (ECM) >> DTC P1148: Closed Loop Control >> DTC Description >> DTC Detection Logic
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DTC Detection Logic

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.
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