🏷️ Basic Information

Make:

Citroën

Model:

BX

Year:

1991

👋 Introduction

Target Audience:

Citroën BX owners, DIY mechanics, independent repair shops, and automotive enthusiasts seeking detailed repair and maintenance information.

Unique Selling Points:

Exceptional ride comfort due to hydropneumatic suspension, distinctive styling, and a reputation for robust engineering.

Value Proposition:

Provides comprehensive, actionable repair guidance for the 1991 Citroën BX, empowering owners to perform maintenance and repairs independently, saving costs and ensuring quality work.

Document Scope:

Covers all major systems and components of the 1991 Citroën BX, offering detailed instructions, diagrams, and specifications for repair and maintenance.

Repair Ease:

Designed to facilitate DIY repairs by providing step-by-step instructions and clear visuals.

📋 Manual Details

Primary Coverage:

Complete service, repair, and maintenance

Estimated Pages:

High volume, likely 500+ pages (typical for comprehensive service manuals)

Type:

Service and Repair Manual / Workshop Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Powertrain:

Engine (all variants), Transmission (manual and automatic), Drivetrain, Fuel System, Exhaust System, Cooling System

Chassis:

Suspension (including HYDRActive/Hydropneumatic systems), Steering, Brakes (including ABS if equipped), Wheels and Tires, Chassis and Body structure

Electrical:

Electrical System, Wiring Diagrams, Lighting, Ignition System, Starting System, Charging System, Instrumentation, Body Electronics, Engine Control Module (ECM) diagnostics

Body And Interior:

Body panels, doors, windows, seals, interior trim, seats, dashboard, HVAC system, security system (if fitted).

Wheels And Tires:

Specifications for wheel sizes, rim offsets, bolt patterns, and recommended tire sizes for various models and trims.

Emission Control:

Details on emission control systems, catalytic converters (if fitted), exhaust gas recirculation (EGR), and related sensors.

Climate Control:

Heater matrix, ventilation system, air conditioning components and servicing (if equipped).

Maintenance:

Scheduled maintenance, oil changes, fluid checks and top-ups, filter replacements, lubrication schedules, inspections

Repair:

Engine overhauls, transmission rebuilds, brake system repairs, suspension component replacement, electrical system diagnostics and repair, body panel repair, interior trim removal/installation

Troubleshooting:

Diagnostic procedures for common and uncommon faults, fault code interpretation (if applicable), symptom-based troubleshooting guides

Diagnostics:

Fault finding procedures for all major systems, including engine management, electrical faults, and mechanical issues. May include diagnostic connector locations and basic testing methods.

Engine Rebuild:

Complete engine disassembly, inspection, component replacement (pistons, rings, bearings, valves), reassembly, and timing procedures.

Suspension Overhaul:

Detailed steps for replacing suspension spheres, anti-roll bars, shock absorbers (if separate), and hydropneumatic system component replacement.

Depth:

Comprehensive, covering everything from basic maintenance to complete engine and transmission rebuilds, including detailed diagnostic procedures and specifications.

Wiring Diagrams:

Detailed, often color-coded, electrical wiring diagrams for all circuits, crucial for diagnosing and repairing electrical issues.

Torques And Specifications:

Precise torque values for all critical fasteners, engine component clearances, bearing preloads, and other vital mechanical specifications.

📊 Manual Specifications

Software Requirements:

Adobe PDF Reader, WinZip or equivalent unzipping utility

Searchability:

PDF format typically allows for text searching of keywords, making it easier to locate specific information.

Quality:

High-resolution scans suitable for clear reading and printing. (Assumed based on industry standard for quality manuals)

Diagram Clarity:

Clear, legible diagrams and illustrations essential for understanding assembly and disassembly procedures.

Illustration Type:

Line drawings, exploded views, and diagnostic flowcharts.

Binding:

Not applicable (Digital PDF format)

Paper Type:

Not applicable (Digital PDF format)

⚙️ Engine Specifications

Engine Variants Covered:

Likely includes the XU series petrol engines (e.g., XU5, XU7, XU9) and potentially HDi diesel variants if available in the 1991 model year, covering carbureted and fuel-injected versions.

Engine Codes Examples:

XU5M (1.6L), XU7JP (1.8L, though less common for '91), XU9J1/XU9M (1.9L). Specific codes would be detailed in the manual.

Engine Displacement Examples:

1.6L (1580cc), 1.9L (1905cc). Specific power and torque figures would depend on the engine variant and market.

Power Output Range:

Typically ranging from 80 PS (approx. 79 bhp) for smaller engines to 115 PS (approx. 113 bhp) for performance variants like the BX GTI.

Fuel Injection Types:

Bosch L-Jetronic, K-Jetronic, or single-point/multi-point injection systems depending on engine and market. Carbureted models would also be covered.

Engine Management System:

Specifics on the Engine Control Unit (ECU) or Motronic/Bosch L-Jetronic management system, including sensor locations and testing.

🔧 Transmission

Transmission Types:

Typically a 5-speed manual gearbox (e.g., Citroën's own design or Peugeot-sourced MA gearbox). An automatic transmission (e.g., ZF 3HP22 or similar) was likely an option.

Gear Ratios:

Manual will provide specific gear ratios for each available gearbox.

Automatic Transmission Details:

Specific details on automatic transmission service, fluid types, and potential repairs would be included if applicable.

Clutch Type:

Dry single-plate clutch for manual transmissions. Hydraulic actuation.

Transmission Fluid Specification:

Manual transmission fluid (MTF) specification (e.g., API GL-4 or GL-5) and capacity. Automatic transmission fluid (ATF) specification (e.g., Dexron II/III) and capacity.

📐 Dimensions

Body Styles:

Hatchback (5-door), Estate/Wagon (Break/Touring).

Length:

Approx. 4230 mm (Hatchback), 4460 mm (Estate). (Estimation)

Wheelbase:

Approx. 2600 mm. (Estimation)

Curb Weight Range:

Approximately 1050-1200 kg, depending on engine and equipment. (Estimation)

Gross Vehicle Weight Rating:

Will be specified in the manual for safe loading limits.

Towing Capacity:

Will be specified in the manual, subject to local regulations and vehicle configuration.

Seating Capacity:

Typically seats 5 occupants.

🛡️ Safety Features

Crash Test Performance:

Historical data on crashworthiness would be presented, though specific formal ratings like Euro NCAP might not be extensive for this era.

Braking System:

Front ventilated discs, rear solid discs. ABS (Anti-lock Braking System) was an option on higher trims or later models. Citroën's advanced hydropneumatic suspension contributed to stability.

Restraint System:

Seat belts (front and rear), potentially pre-tensioners. Airbags were rare or non-existent on many 1991 models.

Chassis Design:

Integral body-shell construction, designed for rigidity and passive safety. Hydropneumatic system also aids in managing chassis loads.

💡 Technology Features

Audio System:

Factory-fitted radio/cassette player (e.g., Clarion, Blaupunkt) with potential for upgraded speakers. Limited connectivity by modern standards.

Display Technology:

Typically analog gauges with a simple digital odometer. Some models might have basic trip computers.

ABS Availability:

Optional on some models, particularly later ones. The manual will detail its operation and servicing.

Cruise Control Availability:

Optional on some higher-spec models. Manual would cover its operation and troubleshooting.

Dashboard Controls:

Features unique 'roller' or 'stalk' controls for various functions, as well as the 'mushroom' button for horn/lights, characteristic of Citroën design.

🔧 Maintenance

Oil Change Interval:

Typically 5,000-10,000 km (3,000-6,000 miles) or 6-12 months, depending on driving conditions and oil type used. Manual will specify exact intervals.

Timing Belt Replacement:

Critical interval, usually between 60,000-100,000 km (37,000-60,000 miles), or a specific time period. Failure to replace can cause catastrophic engine damage.

Engine Oil Specification:

API SG/SH or ACEA A2/A3. Viscosity grades such as 10W-40 or 15W-40 are common. The manual will list specific OEM approvals and recommended grades.

Hydropneumatic Fluid:

Citroën LHS 2 or LHS M hydraulic fluid (mineral-based). Crucial for suspension, brakes, and clutch operation. Incorrect fluid can cause catastrophic system failure.

Coolant Type:

Ethylene glycol-based antifreeze/coolant. Typically a 50/50 mix with distilled water. Manual will specify color and type.

Brake Fluid Specification:

DOT 3 or DOT 4 brake fluid. Crucial for maintaining braking performance and system integrity.

Power Steering Fluid:

Likely requires specific Citroën hydraulic fluid (LHS M or equivalent) due to the integrated hydraulic system, or a dedicated power steering fluid if equipped with a separate system.

Common Faults And Solutions:

Hydropneumatic suspension spheres (loss of pressure, stiffness), hydraulic pump wear, corrosion (especially on sills and wheel arches), electrical gremlins, exhaust system corrosion, potential for water ingress into the ECU on older models.

Suspension Maintenance:

Regular checking and replacement of hydraulic fluid and sphere membranes is vital for maintaining the signature ride quality.

Engine Specific Issues:

Timing belt wear (critical replacement interval), potential head gasket leaks on high-mileage engines, carburetor or fuel injection system issues.

Electrical System Quirks:

Corrosion on earth points, issues with dashboard lighting and switches, problems with central locking or window regulators.

📚 Vehicle History

Citroen Design Philosophy:

Known for innovative and avant-garde automotive design, comfort, and unique engineering solutions, exemplified by its hydropneumatic suspension.

Citroen Bx Development:

Successor to the GS/GSA and positioned below the CX. Known for its distinctive wedge-shaped, aerodynamic styling by Bertone and its advanced hydropneumatic suspension system, offering exceptional ride comfort.

Facelifts And Updates:

The 1991 model likely reflects updates from the 1986 facelift, which included a revised dashboard, improved ergonomics, and minor styling tweaks.

Production Period:

1982-1994. The 1991 model represents a mid-to-late production year, likely featuring updates from earlier models.

🏆 Awards & Recognition

Automotive Journalism Awards:

While specific awards for the 1991 model year might be scarce, the BX was generally praised for its ride comfort and innovative design by automotive press during its production run.