P1633critical severityPowertrain

ECM Malfunction ETCS Circuit

on 2010 Toyota Highlander 3.3L V6 Hybrid · AWD

What this code means

Internal ECM fault related to the Electronic Throttle Control System processor.

Symptoms

  • CEL
  • Limp mode
  • Severely limited throttle
  • Idle only
  • Reduced power

Common causes

  • Internal ECM ETCS failure
  • Power supply issues
  • ECM overheating

Diagnostic steps

  1. Check ECM voltage supply
  2. Monitor ETCS signals
  3. Test throttle body
  4. Check for overheating

Repair notes

Replace ECM.

Other Powertrain codes on this vehicle

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