🏷️ Basic Information Identification Make: Volkswagen Model: Golf Model Variant: Mk4 / A4 Platform Model Subvariant: Jetta Generation Generation Name: Mk4 Platform: A4 Codes Engine Code: AEG 👋 Introduction Market Position Target Audience: Professional automotive technicians, DIY enthusiasts, and owners seeking detailed understanding of their Mk4 Jetta/Golf's electrical system. Competitive Analysis Value Proposition: Provides essential, dealership-level diagnostic information for the AEG engine's electrical system, which is critical for troubleshooting modern vehicle issues. Key Features Focus: Detailed electrical schematics, component identification, and diagnostic procedures for a specific engine variant and vehicle platform. 📋 Manual Details Coverage Areas Scope: Electrical System & Wiring Diagrams Page Count Pages: Highly detailed, often exceeding 150-250 pages depending on specific print run or digital compilation. Manual Type Type: Wiring Diagram Manual / Electrical Troubleshooting Manual (ETM) Language Language: English Format Format: Digital (PDF) 📖 Manual Coverage Systems Covered Electrical Systems: Engine Control Module (ECM), Fuel Injection System, Ignition System, Lighting (Headlights, Taillights, Interior), Power Windows, Power Locks, Sunroof, Wiper System, HVAC Controls, ABS/ESP, Airbag System, Audio System, Instrument Cluster, Speedometer, Tachometer, Gauges, Switches, Relays, Fuses, Body Control Modules (BCM). Procedures Included Troubleshooting: Diagnosis and resolution of electrical faults, short circuits, open circuits, ground faults, voltage drop issues, signal interruptions. Pinpoint testing of circuits and components. Wiring Identification: Color coding of wires, wire gauge identification, connector pinouts, component locations, harness routing schematics. Component Testing: Testing of sensors (e.g., O2 sensors, MAF sensor, Crankshaft Position Sensor), actuators (e.g., fuel injectors, ignition coils), motors, switches, and modules. Technical Depth Depth: Comprehensive, providing detailed schematics for every electrical circuit, allowing for in-depth diagnosis and repair of complex electrical issues. 📊 Manual Specifications File Format Digital Quality: High-resolution, searchable PDF, allowing for easy navigation and printing of specific pages. Text is often OCR'd for searchability. Print Quality Scalability: Diagrams are vector-based or high-resolution raster images, ensuring clarity when magnified for detailed inspection. Binding Type Binding: N/A (Digital PDF) Paper Type Paper Weight: N/A (Digital PDF) ⚙️ Engine Specifications Primary Engine Engine Code: AEG Engine Type: Inline 4-cylinder, naturally aspirated Displacement: 2.0 Liters (1984 cc) Bore X Stroke: 81.0 mm x 95.5 mm Compression Ratio: 10.1:1 Performance Horsepower: 114 hp @ 5200 rpm (approx.) Torque: 122 lb-ft @ 2400 rpm (approx.) Fuel System Fuel Delivery: Electronic Fuel Injection (EFI) - Multi-point Sequential Injection Fuel Type: Unleaded gasoline Engine Management ECM Type: Bosch Motronic (specific model varies, often ME7 variants or similar) Ignition System: Distributorless Ignition System (DIS) with coil packs 🔧 Transmission Standard Type: 5-speed Manual Transmission (e.g., 02J) Optional Type: 4-speed Automatic Transmission (e.g., 01M) Features Traction Control: Optional, often integrated with ESP (Electronic Stability Program) 📐 Dimensions Exterior Length: Approx. 4374 mm (Golf) / 4409 mm (Jetta) Width: Approx. 1735 mm Height: Approx. 1444 mm (Golf) / 1447 mm (Jetta) Weights Curb Weight: Approx. 1300 - 1450 kg (depending on transmission and options) Gross Vehicle Weight Rating: Varies by model and configuration 🛡️ Safety Features Ratings NHTSA Front Impact: Good (IIHS for similar models, NHTSA ratings can vary by year and specific test) NHTSA Side Impact: Good (IIHS for similar models, NHTSA ratings can vary by year and specific test) Active Features ABS: Standard on most models Esp Traction Control: Optional, branded as ESP (Electronic Stabilization Program) Passive Features Airbags: Front airbags standard, side airbags optional. Seatbelts: 3-point front and rear seatbelts with pretensioners. 💡 Technology Features Infotainment Head Unit: Stock head units typically include AM/FM radio, CD player. Aftermarket upgrades are common. Interface is basic by modern standards. Speaker System: Standard 4-6 speaker systems. Driver Assistance Cruise Control: Standard or optional depending on trim level. Rain Sensing Wipers: Optional on higher trim levels. Connectivity Aux Input: Not standard on most models, often requires adapter or aftermarket head unit. Bluetooth: Not standard, available on some later Mk4 models or via aftermarket solutions. 🔧 Maintenance Service Intervals Oil Change: Typically every 7,500 - 10,000 miles (12,000 - 16,000 km) or 1 year, whichever comes first, under normal driving conditions. Refer to specific owner's manual for exact intervals. Spark Plugs: Varies by plug type (e.g., 60,000 - 100,000 miles for platinum/iridium plugs). Consult manual for specifics. Timing Belt: Crucial maintenance item. Typically replaced every 60,000 - 80,000 miles (96,000 - 128,000 km) or 7-10 years due to its interference engine design. Often includes water pump replacement. Fluid Specifications Engine Oil: SAE 5W-40 or 5W-30 Synthetic (API SN, ACEA A3/B4 or C3). Coolant: G12 Plus (Pink) or G12++ Antifreeze/Coolant (50/50 mixture with distilled water). Transmission Fluid Manual: G 005 21 21 (or equivalent GL-4 spec) Manual Transmission Fluid. Transmission Fluid Automatic: G 052 162 (ATF, typically Dexron III/VI compatible, but specific VW spec is critical). Brake Fluid: DOT 4 brake fluid. Known Issues Ignition Coils: Coil-on-plug units can fail prematurely, causing misfires. Oil Leaks: Valve cover gasket, oil pan gasket, and crankshaft seals...