🏷️ Basic Information Identification Make: Cadillac Model: STS Years Covered: 2004, 2005, 2006, 2007 Generation Generation Designation: Second Generation (Northstar platform based) Codes Platform Code: GM Sigma Platform 👋 Introduction Market Position Vehicle Segment: Luxury Sedan Competitive Analysis Competitors: BMW 5 Series, Mercedes-Benz E-Class, Audi A6, Lexus GS Key Features Luxury Appointments: Premium materials, advanced technology, refined ride quality. Performance Orientation: Available V8 engines, refined chassis, rear-wheel or all-wheel drive options. 📋 Manual Details Coverage Areas Coverage Scope: All Models, Engines, Trims, and Transmission Types Page Count Estimated Pages: Comprehensive (exact count not specified, but described as 'Complete Workshop Service Repair Manual') Manual Type Type: Workshop Service and Repair Manual Language Language: English Format Format: Downloadable Digital File (PDF) 📖 Manual Coverage Systems Covered Powertrain: Engine Mechanical, Engine Control System (ECM), Fuel System, Ignition System, Exhaust System, Cooling System, Lubrication System Transmission Drivetrain: Automatic Transmission (e.g., 4T80-E), Drivetrain, Axles, Driveshafts, Differentials Chassis: Suspension System (Front & Rear), Steering System, Brake System (Front & Rear, ABS, Traction Control) Electrical Electronics: Body Control Module (BCM), Powertrain Control Module (PCM), Infotainment System, Lighting Systems, Instrument Cluster, Wiring Diagrams, Diagnostics, Sensors, Actuators Body Interior: Body Repair, Interior Trim, Seats, HVAC System, Doors, Windows, Locks, Body Panels, Bumpers Procedures Included Maintenance: Scheduled Maintenance, Oil Changes, Filter Replacements, Fluid Checks and Replacements, Tune-Ups Repair Overhaul: Engine Rebuilding, Transmission Overhaul, Suspension Component Replacement, Brake Pad/Rotor Replacement, Electrical Component Diagnosis and Replacement Diagnostics Troubleshooting: Diagnostic Trouble Codes (DTCs), Symptom-Based Troubleshooting, Component Testing, Electrical Circuit Diagnosis Installation Replacement: Component Installation and Replacement (e.g., alternators, starters, sensors, body panels) Technical Depth Depth: Comprehensive from basic maintenance to advanced diagnostics and complete rebuild procedures. 📊 Manual Specifications File Format File Type: PDF Print Quality Printability: High-quality, printable by page, chapter, or entire manual. Binding Type Binding Style: N/A (Digital Download) Paper Type Paper Quality: N/A (Digital Download) Software Requirements Required Software: Adobe Reader (free download available) ⚙️ Engine Specifications Primary Engine Engine Option 1: 4.6L Northstar V8 (LD8/L37 variations) Engine Option 2: 4.4L Supercharged Northstar V8 (XLR-V derived for some models, though less common in standard STS lineup for these years, typically 4.6L variants are most prevalent) Engine Option 3: 3.6L LY7 V6 (Optional on some models) Performance 4.6L V8 Horsepower: Approx. 320-330 hp (depending on specific L37/LD8 variant) 4.6L V8 Torque: Approx. 310-315 lb-ft (depending on specific L37/LD8 variant) 3.6L V6 Horsepower: Approx. 255 hp 3.6L V6 Torque: Approx. 250 lb-ft Fuel System Injection Type: Sequential Multi-Port Fuel Injection (MPI) Fuel Type: Premium Unleaded Gasoline (91 octane recommended for optimal performance) Engine Codes Northstar Engine Variants: L37 (performance-oriented), LD8 (torque-oriented) 🔧 Transmission Standard Transmission Type: 6-speed automatic (e.g., 6L80 for some models, 4-speed 4T80-E for earlier V8s, but manual covers all variations) Optional Drivetrain Options: Rear-Wheel Drive (RWD), All-Wheel Drive (AWD) Features Transmission Features: Driver Shift Control (manual shifting capability), performance shift modes. Fluid Specifications Transmission Fluid Type: Dexron-VI (for 6-speed automatics), Dexron-III (for 4-speed automatics) 📐 Dimensions Exterior Wheelbase: Approx. 113.5 inches Length: Approx. 200.5 inches Width: Approx. 72.5 inches Height: Approx. 57.7 inches Weights Curb Weight: Approx. 3,800 - 4,200 lbs (depending on engine and drivetrain) 🛡️ Safety Features Ratings NHTSA Front Impact: 5-Star (for driver and front passenger) NHTSA Side Impact: 5-Star (for front and rear passengers) Active Features Traction Control: Standard (TCS) Electronic Stability Control: Standard (StabiliTrak) Anti Lock Brakes: Standard (ABS) Passive Features Airbags: Frontal airbags, front side-impact airbags, side curtain airbags. Seatbelts: 3-point seatbelts with pretensioners. 💡 Technology Features Infotainment Infotainment System Name: Cadillac User Experience (CUE) was introduced later; for these years, it featured a navigation system, premium audio (e.g., Bose), and climate controls integrated into the dashboard. Audio System: Bose premium sound system with multiple speakers. Navigation: Optional factory navigation system. Driver Assistance Adaptive Cruise Control: Optional feature on some trims. Parking Assist: Optional rear parking assist sensors. Connectivity Bluetooth: Optional Bluetooth hands-free calling integration. Comfort Convenience Keyless Entry Start: Keyless Access and Remote Start. Heated Cooled Seats: Optional heated and ventilated front seats, heated rear seats. 🔧 Maintenance Service Intervals Oil Change Interval: Typically every 5,000 - 7,500 miles or 6 months, depending on driving conditions and oil type used. Transmission Fluid Change: Recommended every 60,000 - 100,000 miles, consult manual for specific intervals by transmission type. Coolant Change: Recommended every 50,000 - 100,000 miles or 5 years, depending on coolant type. Fluid Specifications Engine Oil Type: SAE 5W-30 Synthetic (API SN or newer) Engine Oil Capacity: Approx. 5.0 - 7.0 quarts (depending on engine variant, consult manual) Brake Fluid Type: DOT 3 Power Steering Fluid: Dexron-VI or equivalent power steering fluid. Known Issues Northstar Engine Head Gaskets: While significantly improved from earlier generations, some Northstar engines could still be prone to head gasket issues if overheated or improperly maintained. Manual will cover diagnostic procedures. Vibrations: Some owners reported NVH (Noise,...