P1605high severityPowertrain

Knock Control CPU Malfunction

on 2014 Toyota Highlander 2.7L I4 · AWD

What this code means

The ECM detected a communication failure with the knock control CPU.

Symptoms

  • CEL
  • Engine knock under load
  • Reduced performance
  • Timing retarded to safe value

Common causes

  • Faulty knock CPU in ECM
  • Damaged knock sensor wiring
  • Faulty knock sensor
  • Poor connections

Diagnostic steps

  1. Test knock sensor
  2. Inspect wiring harness
  3. Check ECM operation
  4. Monitor knock retard

Repair notes

Replace knock sensor or ECM.

Other Powertrain codes on this vehicle

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