P0666
Control Module Internal Temperature Sensor A Circuit
A general circuit fault on the ECU's internal temperature sensor A - the sensor that monitors module operating temperature for thermal protection.
A general circuit fault on the ECU's internal temperature sensor A - the sensor that monitors module operating temperature for thermal protection.
Common causes
- high
Internal sensor fault
One of the most commonly reported causes for this code — check this first.
Typical part cost: $440-2200
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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 P0666 mean?
P0666 means "Control Module Internal Temperature Sensor A Circuit". It is a generic OBD-II code that points to a fault in the computer & auxiliary output controls.
What are the most common causes of P0666?
internal sensor fault — 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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