DTC Detection Logic

2008 Infiniti EX35 Base, AWDSECTION DTC Detection Logic

To judge the malfunction of A/F sensor 1, this diagnosis measures response time of the A/F signal computed by ECM from the A/F sensor 1 signal. The time is compensated by engine operating (speed and load), fuel feedback control constant, and the A/F sensor 1 temperature index. Judgment is based on whether the compensated time (the A/F signal cycling time index) is inordinately long or not.

DTC DETECTING CONDITION AND POSSIBLE CAUSE REFERENCE

DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P0133 Air fuel ratio (A/F) sensor 1 (bank 1) circuit slow response
  • The response of the A/F signal computed by ECM from A/F sensor 1 signal takes more than the specified time.
  • Harness or connectors

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

  • A/F sensor 1
  • A/F sensor 1 heater
  • Fuel pressure
  • Fuel injector
  • Intake air leaks
  • Exhaust gas leaks
  • PCV
  • Mass air flow sensor
P0153 Air fuel ratio (A/F) sensor 1 (bank 2) circuit slow response
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.