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Home >> Lexus >> 2019 >> ES 350 Luxury >> Repair and Diagnosis >> External Pages >> Different car >> Section 127 (Engine Control System (A25A-FXS) - Diagnostic Codes (12 Of 20)) >> SFI System >> DTC P0597-14: Thermostat Heater Control Circuit Short to Ground or Open [06/2018 - 08/2020] >> Monitor Description

Monitor Description

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The ECM monitors the output voltage while the thermostat heater is operating.

The thermostat heater turns on and off according to ON/OFF switching of a transistor inside the ECM.

If a continuous mismatch occurs between the ECM transistor state and the output voltage, the ECM determines there is a malfunction in the thermostat heater circuit and stores a DTC.