P0597
Thermostat Heater Control Circuit Open
The map-controlled thermostat - electrically heated to lower its opening temperature on demand for emissions or torque mapping - has an open control circuit. The ECU loses the ability to override coolant flow timing.
The map-controlled thermostat - electrically heated to lower its opening temperature on demand for emissions or torque mapping - has an open control circuit. The ECU loses the ability to override coolant flow timing.
Common causes
- high
Open in heater element or harness
One of the most commonly reported causes for this code — check this first.
Typical part cost: $90-390
- low
Pin pushed back out of connector body
Less common, but worth ruling out after the more likely causes.
Typical part cost: $90-390
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does P0597 mean?
P0597 means "Thermostat Heater Control Circuit Open". It is a generic OBD-II code that points to a fault in the vehicle speed, idle control, auxiliary inputs.
What are the most common causes of P0597?
open in heater element or harness; pin pushed back out of connector body; cracked solder joint inside the module or sensor — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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