1990 BMW 325is StandardFACTORY OEM SERVICE PROCEDURE

O2 Sensor Indicator Test

At 30,000 mile intervals, fuse (.1 amp) opens. Switch closes and O2 sensor service indicator illuminates. When replacing fuse, located inside instrument cluster behind speedometer, ensure ignition switch is in OFF position.For resetting of the O2 Service indicator see SERVICE INTERVAL INDICATORΒ .

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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.