🏷️ Basic Information Identification Make: Subaru Model: Impreza Year: 2004 Codes Chassis Code: GD/GG Platform: Subaru Global Platform (first generation) 👋 Introduction Market Position Segment: Compact/Small Family Car, Rally Sport Heritage Competitive Analysis Key Competitors: Mitsubishi Lancer, Honda Civic, Toyota Corolla, Mazda3 Key Features Drivetrain Advantage: Standard Symmetrical All-Wheel Drive (AWD) across most trims Performance Variants: Availability of turbocharged WRX and STI models Design Philosophy: Practicality, safety, and performance, with rally-inspired DNA 📋 Manual Details Coverage Areas All Systems: Yes Body And Chassis: Yes Engine: Yes Transmission: Yes Drivetrain: Yes Suspension: Yes Steering: Yes Brakes: Yes Electrical System: Yes HVAC: Yes Fuel System: Yes Exhaust System: Yes Cooling System: Yes Ignition System: Yes Emissions Control: Yes Diagnostics: Yes Wiring Diagrams: Yes Troubleshooting: Yes Torque Specifications: Yes Special Tools: Yes Page Count Estimated Pages: ~2000+ Manual Type Type: Factory Service Manual (FSM) Purpose: DIY Repair and Maintenance Language Language: English Format Format: PDF Searchability: Searchable Text Printability: Printable 📖 Manual Coverage Systems Covered Engine Management: ECU, sensors, actuators, fuel injection, ignition timing Powertrain Control: Engine, transmission, AWD system integration Chassis Systems: Suspension, steering, brakes (including ABS), wheel bearings Body Electrical: Lighting, wipers, power accessories, central locking, alarm system Interior Systems: Climate control, airbags, seat belts, instrument cluster, audio systems Procedures Included Routine Maintenance: Oil changes, filter replacements, spark plug service, fluid checks/changes Component Diagnostics: Step-by-step troubleshooting for all major systems Component Removal And Installation: Detailed instructions for disassembling and reassembling all parts Rebuilding Procedures: Engine, transmission, and differential rebuilding guides Alignment And Balancing: Wheel alignment specifications and procedures Air Conditioning Service: Refrigerant handling, leak detection, component replacement Diagnostic Trouble Codes: Definition and troubleshooting steps for OBD-II codes Technical Depth Depth: Comprehensive (from basic maintenance to full engine rebuilds) Diagnostics Level: Advanced electronic diagnostics, including sensor data analysis Repair Complexity: Suitable for both novice DIYers and experienced technicians 📊 Manual Specifications File Format Quality: High resolution, clear text and images Print Quality Clarity: Excellent, designed for clear printing Binding Type Binding: N/A (Digital PDF) Paper Type Paper: N/A (Digital PDF) ⚙️ Engine Specifications Primary Engine Engine Code Na: EJ251 (2.5L Naturally Aspirated) Engine Displacement Na: 2.5 Liters (2457 cc) Engine Configuration Na: Horizontally Opposed (Boxer) 4-cylinder Bore X Stroke Na: 99.5 mm x 79.0 mm Compression Ratio Na: 9.7:1 Horsepower Na: 165 hp @ 5600 rpm (approx.) Torque Na: 166 lb-ft @ 4000 rpm (approx.) Performance Variant Wrx Engine Code Wrx: EJ255 (2.5L Turbocharged) Horsepower Wrx: 227 hp @ 5600 rpm (approx.) Torque Wrx: 235 lb-ft @ 3000 rpm (approx.) Performance Variant Sti Engine Code Sti: EJ257 (2.5L Turbocharged - DOHC) Horsepower Sti: 300 hp @ 6000 rpm (approx.) Torque Sti: 300 lb-ft @ 4000 rpm (approx.) Fuel System Fuel Delivery: Multi-point Fuel Injection (MPI) Recommended Fuel: 87 Octane (NA), 91+ Octane (Turbocharged WRX/STI) Cooling System Coolant Type: Subaru Super Coolant (Blue) or equivalent 🔧 Transmission Standard Transmission Na: 5-Speed Manual Optional Na Transmission Na: 4-Speed Automatic (with AWD) Standard Wrx Transmission Wrx: 5-Speed Manual Standard Sti Transmission Sti: 6-Speed Manual Features AWD System: Symmetrical All-Wheel Drive with Front Helical LSD, Rear Viscous LSD (except STI) Sti AWD Features: Driver Controlled Center Differential (DCCD) 📐 Dimensions Exterior Length: 173.4 - 174.6 inches (depending on model) Width: 68.1 inches Height: 56.1 inches (Sedan) / 55.1 inches (Wagon) Wheelbase: 100.4 inches Ground Clearance: 5.7 - 6.1 inches (depending on model) Weights Curb Weight Na: ~2900 - 3100 lbs (depending on body style/transmission) Curb Weight Wrx: ~3100 - 3200 lbs Curb Weight Sti: ~3200 - 3300 lbs Towing Capacity: Not Recommended/Specified Cargo Trunk Volume Sedan: ~11.4 cu ft Cargo Volume Wagon: ~29.8 cu ft (behind rear seats) 🛡️ Safety Features Ratings NHTSA Front Driver: Good (2004 Model Year) NHTSA Front Passenger: Good (2004 Model Year) NHTSA Side Driver: Good (2004 Model Year - with side airbags) NHTSA Side Rear Passenger: Good (2004 Model Year - with side airbags) IIHS Front Impact: Good IIHS Side Impact: Acceptable (without side airbags) / Good (with side airbags) Active Features ABS: Standard on all trims Traction Control: Available on some trims Electronic Stability Control: Not widely available on this generation Passive Features Airbags Front: Standard Dual Front SRS Airbags Airbags Side: Optional Front Side-Impact Airbags Seatbelts: 3-point front and rear seatbelts with pretensioners Child Seat Anchors: LATCH system 💡 Technology Features Infotainment Audio System: Factory AM/FM/CD player with optional CD changer. Basic speaker setup. Navigation: Not available on most trims. Aftermarket solutions were common. Driver Assistance Cruise Control: Standard on most trims Keyless Entry: Available on higher trims Connectivity Auxiliary Input: Typically not standard. Requires aftermarket modification. 🔧 Maintenance Service Intervals Oil Change Interval: Every 3,750 miles or 3 months (severe conditions) / 7,500 miles or 6 months (normal conditions), check manual for specifics. Air Filter Replacement: Every 15,000 miles or 12 months Spark Plug Replacement: Every 60,000 miles...