P0597 Thermostat Heater Control Circuit Open

OBD2 Code: P0597

Description: Thermostat Heater Control Circuit Open

Definition: This code indicates that there is an open circuit in the thermostat heater control, which means the engine control module (ECM) has detected a malfunction with the thermostat heater control circuit.

P0597 – Thermostat Heater Control Circuit Open

Typical Severity: Moderate

Common Causes

P0597 – Thermostat Heater Control Circuit Open

Common causes:

• Faulty thermostat heater control circuit
• Open or short in the wiring of the thermostat heater control circuit
• Corroded or loose connections in the thermostat heater control circuit
• Defective engine coolant temperature sensor

 

Common Misdiagnosis

OBD2 Code: P0597

Description: Thermostat Heater Control Circuit Open

Common Misdiagnosis: Replacing the thermostat without checking for wiring issues or a faulty control module.

 

Common Diagnostic Steps

OBD2 Code: P0597

Description: Thermostat Heater Control Circuit Open

• Check for any blown fuses related to the thermostat heater circuit.
• Inspect the wiring and connectors for damage, corrosion, or disconnection in the thermostat heater control circuit.
• Test the thermostat heater element for continuity using a multimeter.
• Verify that there is power and ground at the thermostat connector with a test light or multimeter.
• Examine the Engine Control Module (ECM) for any signs of malfunction or failure.
• If applicable, check for any technical service bulletins (TSBs) related to this code on your vehicle model.
• Clear the code and perform a road test to see if it returns after repairs are made.