P0597 Thermostat Heater Control Circuit Ford Focus: What It Means, Why It Happens, and How to Fix It
P0597 on a Ford Focus means the PCM has detected an open circuit in the thermostat heater control circuit: a unique fault that most drivers have never heard of because Ford uses an electrically heated thermostat that most other manufacturers do not, and when the heater element in the thermostat fails or loses its circuit […]