P3402high severityPowertrain

Onboard Charger Output Current Regulation Fault

on 2010 Toyota Highlander 3.3L V6 Hybrid · AWD

What this code means

The OBC is unable to maintain stable output current during charging. The charge current fluctuates or cannot reach the target level.

Symptoms

  • Charging slower than expected
  • Charge current fluctuating
  • Extended charge times
  • Charging session interruptions
  • Battery not reaching full charge

Common causes

  • OBC output stage degradation
  • Battery resistance affecting current control
  • OBC temperature causing derating
  • Output current sensor drift
  • Software calibration error

Diagnostic steps

  1. Monitor charge current and voltage during session
  2. Check OBC temperature during charging
  3. Compare actual vs target charge current
  4. Test at different charge levels
  5. Review OBC software version

Repair notes

Replace OBC if output regulation is out of specification. Software update may address calibration issues.

Other Powertrain codes on this vehicle

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