Segment:
Compact car, often positioned in rally-inspired performance variants.
Key Competitors:
Honda Civic, Toyota Corolla, Mazda3, Volkswagen Golf, Ford Focus
Vehicle Selling Points:
Symmetrical All-Wheel Drive (standard on most trims), boxer engine, robust build quality, practical interior, sporty handling (especially WRX and STI variants).
Value Proposition:
Essential tool for owners and technicians to maintain, diagnose, and repair the 2009 Subaru Impreza, ensuring optimal performance and longevity. Facilitates DIY repairs and accurate professional servicing.
Engine Systems:
Engine mechanical, lubrication, cooling, fuel, ignition, emissions control, engine management (ECU)
Transmission Systems:
Manual transmission, automatic transmission, clutch, drivetrain (driveshafts, differentials)
Chassis Systems:
Suspension (front and rear), steering, brakes (hydraulic, ABS, EBD), wheels, tires
Electrical Systems:
Battery, charging system, starting system, lighting, instrumentation, power windows, mirrors, door locks, wipers, horn, body control modules, multiplex integrated control system
Body And Interior:
Body construction, panels, doors, hood, trunk, interior trim, seats, airbags, climate control system (HVAC)
Maintenance Procedures:
Scheduled maintenance, oil changes, filter replacements, fluid checks and changes, spark plug replacement, brake pad replacement, tire rotation
Repair Procedures:
Engine component replacement (pistons, rings, valves, bearings), cylinder head overhaul, transmission overhaul, brake system repair, suspension component replacement, steering rack replacement, electrical component diagnosis and repair
Troubleshooting:
Diagnostic charts, fault code interpretation, symptom-based troubleshooting guides
Specifications And Data:
Torque specifications, clearances, fluid capacities, electrical component specifications, diagnostic parameters
Electrical Diagnostics:
Wiring diagrams, component locations, diagnostic trouble codes (DTCs) and their meanings, troubleshooting flowcharts for electrical circuits.
Body Repair:
Body panel replacement procedures, structural repair guidelines, door mechanism adjustments, glass replacement, and underbody corrosion protection.
Climate Control Repair:
HVAC system diagnosis, refrigerant handling and charging, component replacement (compressor, condenser, evaporator, blower motor), heater core replacement, control panel troubleshooting.
Engine Rebuilding:
Detailed procedures for engine disassembly, component inspection, cleaning, measurement, and reassembly, including crankshaft, connecting rods, pistons, and cylinder head.
Depth Of Information:
Comprehensive, suitable for professional technicians and advanced DIY mechanics. Covers detailed disassembly, assembly, diagnosis, and repair procedures.
Diagnostic Tools:
References to using Subaru Select Monitor (SSM) or equivalent OBD-II scanners for advanced diagnostics and data logging.
Engine Type:
Horizontally-opposed (Boxer) 4-cylinder
Displacement Na:
2.5 Liters (2457 cc)
Engine Codes Common:
EJ25 (various sub-variants like EJ253, EJ255, EJ257 for NA, Turbo, STI respectively)
Horsepower Na:
Approx. 170 hp (NA models), 265 hp (WRX), 305 hp (STI)
Torque Na:
Approx. 170 lb-ft (NA models), 244 lb-ft (WRX), 290 lb-ft (STI)
Fuel Delivery:
Electronic Fuel Injection (EFI)
Fuel Type:
Unleaded gasoline (91 octane or higher recommended for turbo models)
ECU Type:
Engine Control Unit (ECU) with OBD-II diagnostics
Engine Codes Specific Variants
Ej253:
Naturally aspirated 2.5L SOHC (used in Impreza 2.5i)
Ej255:
Turbocharged 2.5L DOHC (used in Impreza WRX)
Ej257:
Turbocharged 2.5L DOHC (used in Impreza WRX STI, higher output)
Standard Transmission:
5-speed manual transmission
Optional Transmission:
4-speed automatic transmission (with optional Sportshift paddle shifters on some trims)
Drivetrain Layout:
Symmetrical All-Wheel Drive (AWD) standard on most trims, RWD only on certain earlier generations/specific trims globally, but AWD is characteristic of 2009 Impreza.
Manual Transmission Fluid Spec:
Subaru Extra-S Gear Oil (or equivalent API GL-5, 75W-90 viscosity)
Automatic Transmission Fluid Spec:
Subaru ATF-HP (or equivalent DEXRON III/MERCON compatible fluid, check specific manual for exact compatibility)
NHTSA Rating Sedan 2009:
Frontal Crash: 5 Stars, Side Crash: 5 Stars, Rollover: 4 Stars
IIHS Rating 2009:
Top Safety Pick
Active Safety Systems:
Anti-lock Braking System (ABS), Electronic Brake-force Distribution (EBD), Brake Assist, Traction Control System (TCS), Vehicle Dynamics Control (VDC)
Passive Safety Features:
Driver and front passenger airbags, front side-impact airbags, side curtain airbags (all rows), active head restraints, front seatbelt pretensioners
Oil Change Interval Miles:
Every 3,750 miles or 6 months (severe service) or 7,500 miles or 12 months (normal service), depending on driving conditions and oil type used. Consult manual for specifics.
Air Filter Replacement Miles:
Every 15,000 - 30,000 miles, or as needed based on conditions.
Spark Plug Replacement Miles:
Approximately 60,000 - 100,000 miles for iridium-tipped plugs.
Timing Belt Replacement Miles:
Approximately 105,000 miles or 105 months. Crucial for interference engines like the EJ series.
Engine Oil Spec:
SAE 0W-20 (synthetic) for most naturally aspirated models, SAE 5W-30 (synthetic) for WRX/STI models. Always verify with owner's manual or oil cap.
Coolant Spec:
Subaru Super Coolant (Blue) or equivalent P-HOAT ethylene glycol based coolant.
Brake Fluid Spec:
DOT 3 or DOT 4 brake fluid.
Power Steering Fluid Spec:
Subaru All-Wheel Drive Power Steering Fluid (or DEXRON III compatible)
Differential Fluid Spec Front:
API GL-5, SAE 75W-90
Differential Fluid Spec Rear:
API GL-5, SAE 75W-90 (for manual transmission AWD), specific LSD fluid for STI models (check manual).
Common Issues Engine:
Head gasket leaks (especially on earlier EJ25 engines, though less prevalent on 2009 models compared to older ones), oil consumption, turbocharger wear (on WRX/STI).
Common Issues Suspension:
Worn sway bar links, front strut mounts, and rear trailing arm bushings can lead to noise and handling degradation.
Common Issues Electrical:
Intermittent issues with power windows, door lock actuators, and sometimes alternator failure.
Common Issues Transmission:
Clutch wear (manual), torque converter issues (automatic), differential whine.