Description
Product Overview
Bosch ABS/ESP ECU and hydraulic pump assembly designed for Citroen Xsara vehicles within the PSA group. This unit integrates the electronic control unit (ECU) with the hydraulic pump/block to manage Anti‑Lock Braking (ABS) and Electronic Stability Program (ESP) functions, maintaining vehicle braking safety and stability control under demanding conditions.
Key Functions
The assembly modulates brake pressure during wheel slip events, operates the high‑pressure pump to restore hydraulic pressure when valves isolate a circuit, and communicates with vehicle stability systems to assist yaw and traction control. It is a critical safety component that directly affects braking performance and vehicle stability.
Common Faults And Causes
Typical symptoms include illuminated ABS or ESP warning lights, reduced ABS function, unusual pump or valve noises, intermittent operation, longer stopping distances, or a soft/spongy brake pedal. Common causes are electrical connector corrosion, internal valve wear, motor failure, moisture ingress, or wiring faults. Faults are often diagnosed by fault codes stored in the ABS/ESP control unit.
Replacement And Installation
Replacement should follow safe workshop practice: disconnect the vehicle battery first, read and record ABS/ESP fault codes, relieve system pressure, and clearly mark brake lines before disconnecting. Unbolt the module from its bracket, transfer any brackets or sensors if required, fit the replacement unit, reconnect brake lines to correct torque, and bleed the brake system thoroughly to remove air. After mechanical installation, clear fault codes and perform ABS/ESP adaptation and coding using an appropriate diagnostic tool. Proper diagnostic work and controlled test driving are recommended to confirm full functionality.
Why Units Fail
Failures commonly result from long‑term exposure to moisture and road salts, corrosion of electrical connectors, internal valve or motor wear, or electronic faults due to voltage spikes. Regular inspections and attention to electrical connections can prolong service life.
Compatibility
Direct fit for Citroen Xsara models and compatible PSA group vehicles using the listed part numbers. Always verify compatibility with the vehicle VIN or existing part number before purchase, as identical housings can sometimes differ by software or connector variant.
Technical Information
- Manufacturer: Bosch
- Model: Citroen Xsara (PSA Group)
- Product Codes: 0265950057; 9641975380; 4541C7
- Other Numbers: 265950057; 4541C7; 9641975380
Suitable for professional mechanics and experienced DIYers. Verify part numbers and prepare for diagnostic coding and complete brake bleeding after installation to ensure safe operation.
