Description
Overview
The Denso Heater Servo Motor EAB251 6447WZ is a direct-fit HVAC actuator designed for Citroën C4 Picasso and compatible PSA Citroën/Peugeot vehicles. This tested used unit restores precise control of blend and air distribution flaps, helping maintain cabin comfort and reliable climate control performance.
Technical Information
- Manufacturer: Denso
- Model: Citroën C4 Picasso
- Product Codes: EAB251, 6447WZ
- Other Numbers: A 21200500
Function And Common Symptoms
The heater servo motor operates dampers inside the HVAC box to direct heated or cooled air to the desired vents. Common failure symptoms include clicking noises from the dashboard, loss of airflow direction control, incorrect air temperature mixing, or HVAC fault codes. Failures most often result from worn plastic gears, internal motor wear, position-sensor (potentiometer) faults, or connector/corrosion issues.
Replacement And Installation
Replacement is straightforward for experienced mechanics and confident DIYers. General steps:
- Disconnect the vehicle battery before starting work.
- Access the actuator through the glovebox or lower dashboard panels; remove trim as required.
- Unplug the electrical connector and remove the mounting screws or clips.
- Fit the replacement unit, secure mounting fasteners, reconnect the electrical harness and restore battery power.
- Run the HVAC system through its full range to verify proper movement and perform any vehicle-specific calibration if required.
If you are unsure about accessing HVAC components, have a professional technician perform the replacement to avoid damage to the system.
Durability And Advice
HVAC actuators can last many years but may fail sooner with heavy use, moisture ingress or contaminated cabin air. When replacing the servo motor, verify fitment using the product codes above and inspect related linkages, seals and connectors to prevent repeat failures.
Why Choose This Unit
This Denso EAB251 6447WZ heater servo motor provides a cost-effective alternative to a new part while maintaining OEM-style fitment and function. Ideal for workshops and DIY mechanics seeking a reliable HVAC actuator replacement for Citroën C4 Picasso models. Always confirm compatibility by product codes before purchase.
