Description
Hydraulic brake control unit, ABS/ESP pump, unit, Bosch ABS block. For CITROËN C4 PICASSO vehicles. From a car with an automated (robotic) gearbox.
Overview
This Bosch ABS/ESP hydraulic control unit is a direct-fit module designed for Citroën C4 Picasso models. It combines the high-pressure pump, hydraulic block and electronic control functions that manage ABS and Electronic Stability Program interventions. Supplied with original part numbers commonly used when searching for replacements, this unit is suitable for workshops and DIY mechanics who need a reliable replacement to restore braking stability and ABS functionality.
Key Features
- Integrated Hydraulic Block And Pump: Controls brake pressure modulation during ABS and ESP events.
- Bosch Technology: Robust valve and motor design used on Stellantis platforms.
- Direct Replacement: Matches original mounting points and electrical connectors for Citroën C4 Picasso.
- Ideal For Repairs After Pump Or Valve Failure: Restores proper ABS/ESP operation when the hydraulic unit is defective.
Technical Information
- Manufacturer: Bosch
- Model: Citroën C4 Picasso
- Product Codes: 9665106680, 0265950962, 265950962
- Additional Numbers: 4541EY, 4541EZ, 4541QE
- Origin: Unit Removed From Vehicle With Automated (Robotic) Gearbox
Symptoms Indicating Replacement Is Needed
- ABS Or ESP Warning Light Illuminated On Dashboard.
- Intermittent Or Continuous ABS Pump Noise Under Braking.
- Reduced Brake Pedal Feel, Pulsation Or Unusual Brake Behavior During Emergency Braking.
- Frequent Or Unexplained Activation Of The Pump During Normal Driving.
Most Common Causes Of Failure
- Contaminated Or Moisture-Laden Brake Fluid Causing Corrosion Inside The Hydraulic Block.
- Electrical Faults – Corroded Connectors Or Failed Motor/Valves.
- Thermal Stress And Wear After High Mileage Or Heavy Use.
- Related Sensor Failures (Wheel Speed Sensors) Causing Excessive Pump Operation And Premature Wear.
Installation Recommendations
Before Work: Always Disconnect The Battery And Follow Manufacturer Safety Procedures To Avoid Damage To Electronic Systems. Work Should Be Performed By A Qualified Mechanic Or Experienced DIY Technician.
Replacement Steps (General Guideline):
- Park Vehicle Safely, Chock Wheels And Disconnect Negative Battery Terminal.
- Access The ABS/ESP Unit (Often Located In Engine Bay) And Carefully Disconnect Electrical Connectors.
- Cap Brake Lines Immediately After Disconnection To Minimize Fluid Loss And Contamination.
- Unbolt The Hydraulic Unit From Its Mounting Carrier And Remove It From The Vehicle.
- Install Replacement Unit, Reconnect Brake Lines And Electrical Connectors, Respecting Manufacturer Torque Values For Line Fittings.
- Refill Brake Fluid With Correct Specified Fluid And Bleed The Brake System Thoroughly. Use A Diagnostic Tool To Activate The Pump And Perform The Automatic Bleeding Procedure If Available.
- Clear Fault Codes And Verify Proper Operation Of ABS/ESP Systems During A Road Test.
Additional Recommendations: Replace Brake Fluid And Inspect Wheel Speed Sensors And Wiring While Replacing The Unit. Ensure All Connectors Are Clean And Corrosion-Free.
Notes On Coding And Initialization
After Replacement It May Be Necessary To Perform Initialization Or ABS Self-Tests Using A Compatible Diagnostic Tool. Some Vehicles Require Module Adaptation Or System Bleeding Sequences That Are Best Performed With Manufacturer-Level Equipment.
Why Choose This Part
Part Numbers And OEM Cross-References Included Above Make This Unit Easy To Find For Mechanics Searching By Code. The Bosch Hydraulic Block Is A Common Service Replacement For Citroën C4 Picasso Vehicles And Restores Critical ABS/ESP Safety Functions When The Original Unit Fails.
