P1115moderate severityPowertrain

Engine Coolant Temperature Sensor Circuit Malfunction

on 2020 Toyota RAV4 2.5L I4 · AWD

What this code means

The engine coolant temperature sensor circuit has failed or is out of range. The ECM cannot accurately read engine temperature for fuel and fan control.

Symptoms

  • Check engine light on
  • Hard cold starts
  • Cooling fan running abnormally

Common causes

  • Faulty ECT sensor
  • Damaged wiring or connector
  • Low coolant level
  • Faulty ECM

Diagnostic steps

  1. Check coolant level
  2. Read ECT sensor live data
  3. Test sensor resistance vs temperature
  4. Replace ECT sensor if out of spec
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