Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (2GR-FKS) - Diagnostic Codes (5 Of 6) >> SFI System >> DTC P0597-14: Thermostat Heater Control Circuit Short to Ground or Open [12/2019 - 10/2022] >> Typical Malfunction Thresholds