This suspension control unit (ECU) is designed to manage and regulate the vehicle’s suspension functions, improving ride comfort and stability. It is commonly referenced with OE number 9664385080 and internal codes 5273N1, 5273P4 and 5273N2. The unit is suitable for technicians and DIY mechanics who need a direct replacement part for Citroën and Peugeot models that use these references. Including clear product codes in the listing increases findability for customers searching by part number.

Function And Application

The unit Processes Signals From Ride Height And Speed Sensors And Sends Commands To Suspension Actuators And Valves To Maintain Correct Vehicle Level And Damping Characteristics. It Communicates With Other Vehicle Control Modules To Coordinate Stability Systems. Typical Applications Include Vehicles Equipped With Height-Adaptive Or Electronically Controlled Suspension, Where Precise Control Of Ride Height And Response Is Required.

Technical Information

• Manufacturer: Stellantis / Citroën / Peugeot
• Model: Citroën C4 Picasso (Source Vehicle)
• Product Codes: 9664385080
• Additional Numbers: 5273N1, 5273P4, 5273N2

Replacement And Installation

Replacement of the Suspension Control Unit Should Be Carried Out By A Mechanic Or An Experienced DIYer Comfortable With Vehicle Electronics. Typical Steps:

• Disconnect The Battery Before Starting To Prevent Short Circuits And Protect Electronic Components.
• Locate The Unit According To The Vehicle’s Service Manual — Access May Require Removal Of Interior Trim Or Engine Bay Covers.
• Carefully Unplug Electrical Connectors And Remove Mounting Fasteners. Inspect Connectors And Wiring For Corrosion Or Damage.
• Install The New Unit, Secure Fasteners, Reconnect Plugs And Reconnect The Battery.
• Verify System Operation And Clear Any Fault Codes Using A Compatible Diagnostic Tool. Some Vehicles May Require Initialization Or Adaptation Procedures After Replacement.

Installation Recommendations

• Always Disconnect The Battery Before Removal And Reconnection To Avoid Damaging The Unit.
• Protect Connectors From Moisture And Clean Corroded Contacts Prior To Reinstallation.
• Use Proper Tools And Follow Manufacturer Torque Specifications For Fasteners.
• Perform A Full System Check With A Diagnostic Scanner After Installation To Confirm Correct Operation And To Reset Fault Codes.
• If Uncertain About Coding Or Initialization Steps, Seek Assistance From A Technician With PSA Diagnostic Equipment.

Why This Part Commonly Fails

Common Failure Causes Include Water Ingress And Corrosion Of Electrical Connectors, Electrical Surges Or Short Circuits, Mechanical Damage From Road Debris Or Improper Handling, And Age-Related Wear Of Internal Electronic Components. Fault Symptoms Can Include Incorrect Ride Height, Fault Codes Related To Suspension Sensors Or Actuators, And Intermittent Communication Errors With Other Control Modules.

Notes For Buyers

Search By OE Or Internal Codes (9664385080, 5273N1, 5273P4, 5273N2) To Ensure You Locate The Correct Unit. The Unit Originates From A Citroën C4 Picasso And Is Supplied As Shown In The Listing.

Overview

This suspension control unit (electronic control module) regulates the vehicle’s suspension system by reading position and acceleration sensors and commanding actuators/valves to adjust ride height and damping. Designed for professionals and experienced DIYers, the unit is commonly sought under original part numbers such as 9665811380, 0X080336, 5273N1, 5273P4 and 5273N2. Replacing the control unit restores correct suspension behaviour, ride comfort and vehicle leveling when the original module fails.

Technical Information

• Manufacturer: Stellantis (Citroën / Peugeot)
• Model: Citroën C4 Picasso
• Product Codes: 9665811380, 0X080336
• Additional Numbers: 5273N1, 5273P4, 5273N2

Compatibility

Unit originates from Citroën C4 Picasso. Identical or similar control units may be used across other Citroën and Peugeot models that share the same electronic suspension architecture; confirm compatibility by matching the product codes listed above. Searching by the OE numbers increases the chance of finding the correct replacement quickly.

Replacement Procedure

Replacement should be performed by a skilled mechanic or an experienced enthusiast with the right tools. Typical steps:

• Park the vehicle on a level surface and secure it. Always follow the vehicle manufacturer’s safety instructions.
• Disconnect the battery before starting to avoid electrical damage to the module and vehicle electronics.
• Raise the vehicle if needed and access the control unit location (consult vehicle repair manual for exact position; often mounted in the engine bay or underbody area protected from debris).
• Remove electrical connectors and mounting fasteners, noting connector positions and orientations.
• Install the replacement unit, secure all fasteners and reconnect connectors ensuring clean, corrosion-free contacts.
• Reconnect the battery and perform any required initialization or system checks as described by the manufacturer.

Installation Recommendations

• Always Disconnect The Battery Before Removing Or Fitting The Unit To Prevent Damage.
• Inspect Connectors And Wiring For Corrosion Or Damage; Clean Contacts If Necessary.
• Use A Service Manual Or Manufacturer Procedures For Access And Torque Values.
• After Installation, Verify Suspension Operation And Error Codes With A Diagnostic Tool; Clear Faults Only After Confirming The Root Cause.

Most Common Failure Causes

Suspension control units typically fail due to moisture ingress and corrosion on connectors, impact or vibration damage, electrical short circuits or power surges, and internal component aging. Fault symptoms include uneven ride height, warning lights related to suspension faults, harsh or soft damping, or loss of automatic leveling. Regular inspection of seals and wiring looms reduces the risk of premature failure.

Who Should Buy

Recommended for professional workshops, independent mechanics and competent DIY owners who can identify parts by OE numbers and perform electrical and mechanical replacement procedures. The presence of OE codes in the description helps quick searching and identification in parts catalogs and search engines.