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Home >> Infiniti >> 2007 >> QX56 AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P0451 To P1217 >> DTC P1148, P1168 Closed Loop Control >> On Board Diagnosis Logic

On Board Diagnosis Logic

These self-diagnoses have the one trip detection logic. 

DTC DETECTING CONDITION

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

    [The 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)
The closed loop control function for bank 2 does not operate even when vehicle is driving in the specified condition.

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.