Description
Interior Air Temperature Sensor for Citroën and Peugeot vehicles
This used interior temperature sensor (Part Number 6445YY) is suitable for a range of Citroën and Peugeot models and is commonly fitted to the HVAC system to provide accurate cabin temperature feedback for automatic climate control. Ideal for professional mechanics and competent DIYers, the sensor helps restore correct temperature regulation, reduce compressor hunting and improve occupant comfort. Many technicians and customers search for this part by the code 6445YY, so the reference is included prominently for quick identification.
Technical Information
- Manufacturer: Stellantis / Citroën / Peugeot
- Model: Citroën C4; Citroën C5 X7; Peugeot 307; Peugeot 407
- Product Codes: 6445YY
- Additional Numbers: —
Function and Purpose
The interior air temperature sensor measures the temperature of the cabin air and sends this signal to the climate control module. The control unit uses the reading to regulate heating, air conditioning, fan speed and recirculation to maintain the set temperature. A correctly working sensor is critical for stable automatic climate control operation and passenger comfort.
Common Symptoms of Failure
- Incorrect or erratic cabin temperature readings on the climate control display.
- Automatic HVAC failing to reach or maintain the set temperature.
- Continuous or frequent air conditioning compressor cycling (hunting).
- Unusual climate behaviour such as incorrect blend door activation or persistent recirculation.
- Diagnostic trouble codes related to cabin temperature sensor or HVAC system reported by the climate control module.
Why This Part Most Commonly Fails
Ambient and cabin temperature sensors are usually solid-state thermistors that can degrade over time. Typical failure causes include moisture ingress and condensation in the ventilation ducts, connector corrosion, wiring or connector damage during servicing, contamination by dust and debris, and long-term drift due to age. Mechanical damage from improper removal or impact can also render the sensor unreliable.
Installation Recommendations
Replacement is straightforward for experienced technicians but requires attention to detail. Typical steps:
- Locate the sensor: it is usually mounted in or on the HVAC housing or ventilation ducting behind the dashboard or near the cabin air filter area; exact position depends on model.
- Remove relevant trim or access panels to reach the sensor without forcing surrounding parts.
- Disconnect the electrical connector carefully and release any retaining clip or fastener holding the sensor.
- Install the new sensor, ensuring correct orientation and a secure, weatherproof connection. Replace any damaged seals or clips.
- Reassemble trims and test the climate control system: check that cabin temperature readings are stable and that automatic regulation functions properly.
Use basic diagnostic equipment where available to monitor sensor output and verify correct operation after replacement.
Additional Notes
Searchable part number 6445YY and the listed vehicle models are included to help with quick identification. If symptoms are intermittent, inspect wiring and connector integrity before replacing the sensor, since connector corrosion and wiring faults are a common root cause of apparent sensor failure.
