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2019 MAZDA MAZDA3
2.0L I4•AWD•AUTOMATIC•gas
6 active safety recalls on this vehicle — view recalls
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Repairs0Labor551Torque3627Fluid8DTC919Battery1Maintenance0Recalls6
P3602moderate severityPowertrain

Intelligent Battery Sensor (IBS) Circuit Malfunction

on 2019 Mazda Mazda3 2.0L I4 · AWD

What this code means

The intelligent battery sensor that monitors 12V battery current, voltage, and temperature has a circuit fault. The IBS is critical for start-stop and energy management.

Symptoms

  • Start-stop disabled
  • Battery charge management affected
  • Incorrect battery status display
  • Alternator not properly regulated
  • Parasitic draw calculation incorrect

Common causes

  • IBS sensor failure
  • Corroded battery terminal affecting IBS
  • IBS wiring damage
  • Battery replaced without IBS re-registration
  • IBS communication fault

Diagnostic steps

  1. Read IBS data via scan tool
  2. Check IBS connector and mounting
  3. Test IBS communication on LIN bus
  4. Verify battery registration status
  5. Measure IBS signals vs actual battery parameters

Repair notes

Replace IBS sensor if faulty. After battery replacement, always register new battery with the IBS/BMS system.

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🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Lexus & Toyota Mechanic · 20+ years. Spot an error? Use the Help link above — a human reads every report.
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