Powertrain
generic / SAE
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.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number6 / 66
Possible causes
- Internal sensor fault high
Symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 400–2000 €
- Estimated time: 2–6 h
- Component: ecu internal temperature sensor a
- MIL / check engine light
Sources
References
sae:J2012