This comprehensive 2004 Cadillac STS Service and Repair Manual provides detailed instructions, diagrams, and specifications for maintaining, servicing, diagnosing, and repairing your vehicle. It covers all models and all repairs, from A to Z. This is the same manual used by technicians at dealerships, offering you the most accurate and up-to-date information available. The manual includes step-by-step instructions, illustrations, wiring schematics, and specifications to guide you through every repair process. You'll find information on a wide range of topics including: * **Maintenance:** Routine maintenance schedules, fluid checks, and replacement procedures. * **Engine:** Engine operation, troubleshooting, repair procedures, and component specifications. * **Control System:** Engine control systems, electronic components, and diagnostics. * **Mechanical:** Transmission, drivetrain, brakes, suspension, steering, and more. * **Fuel Service Specifications:** Fuel system components, fuel injection systems, and fuel lines. * **Emission Control:** Emissions systems, catalytic converters, and exhaust systems. * **Intake Exhaust Cooling:** Cooling system components, radiator, thermostat, and cooling fans. * **Lube:** Lubrication systems, oil changes, and filter replacements. * **Ignition Starting Charging:** Ignition systems, starters, and charging systems. * **Auto Transmission Clutch:** Automatic transmission operation, troubleshooting, and repair. * **Manual Transmission:** Manual transmission operation, troubleshooting, and repair. * **Transfer Propeller Shaft:** Drivetrain components, axles, and transfer cases. * **Drive Shaft:** Drive shaft components, universal joints, and bearings. * **Differential:** Differential operation, troubleshooting, and repair. * **Axle Suspension:** Suspension components, shocks, struts, and springs. * **Tire & Wheel:** Tire specifications, wheel alignment, and tire pressure. * **Brake Control:** Brake system components, brake lines, and hydraulic systems. * **Brake:** Brake pad and shoe replacement, rotor and drum machining, and brake system bleeding. * **Parking Brake:** Parking brake operation, adjustment, and repair. * **Steering Column:** Steering column components, steering wheel, and steering shaft. * **Power Steering:** Power steering operation, troubleshooting, and repair. * **Air Condition:** Air conditioning systems, refrigerant charging, and component repair. * **Suppl Restraint System:** Airbag systems, seatbelt pretensioners, and sensor diagnostics. * **Seat Belt:** Seatbelt operation, adjustment, and replacement. * **Engine Immobilizer:** Anti-theft systems and immobilizer operation. * **Cruise Control:** Cruise control operation, adjustment, and repair. * **Wiper & Washer:** Windshield wiper and washer systems, motor replacement, and switch operation. * **Door Lock:** Door lock mechanisms, electronic door locks, and power window operation. * **Meter Audio/Visual:** Instrument cluster operation, gauge readings, and warning lights. * **Horn:** Horn operation, troubleshooting, and replacement. * **Windshield/Glass Mirror:** Windshield replacement, window operation, and mirror adjustments. * **Instrument Panel:** Instrument panel components, switches, and controls. * **Seat:** Seat adjustments, seat heating and ventilation systems, and seatbelt operation. * **Engine Hood/ Door:** Hood and door latch operation, adjustment, and replacement. * **Exterior & Interior:** Exterior and interior components, trim pieces, and upholstery. * **Electrical:** Electrical systems, wiring diagrams, and circuit troubleshooting. * **Multiplex/ Can Communication:** On-board computer systems, communication protocols, and diagnostic procedures. This manual is designed to be easy to use and navigate, enabling you to find the information you need quickly and efficiently.

The 2004 Cadillac STS is a mid-size luxury sedan that represents a significant shift in Cadillac's design philosophy. Reintroduced in 2005, the STS was the flagship model for Cadillac, showcasing a more modern and sophisticated aesthetic than its predecessors. This generation, spanning from 2005 to 2011, was based on the GM Sigma platform and featured an elegant and assertive exterior design, with sharp lines, a prominent grille, and distinctive taillights. The interior reflected a similar level of refinement, boasting high-quality materials, comfortable seating, and an array of advanced technology features. The STS offered a range of powertrain options, including a 3.6L V6 and a 4.6L Northstar V8 engine, providing a blend of performance and comfort. The 2004 Cadillac STS was praised for its luxurious amenities and driving dynamics, offering a smooth and refined ride, along with responsive handling and ample power. However, some critics pointed out potential reliability issues with the Northstar engine, particularly those related to valve seal leaks and head gasket failures. Yet, the STS remained a popular choice for discerning buyers seeking a blend of performance, luxury, and prestige. The 2004 Cadillac STS was a significant step forward for Cadillac, marking a departure from its traditional design language and embracing a more modern and dynamic approach. A service and repair manual for this model would serve as an invaluable tool for both professional technicians and DIY enthusiasts, providing detailed guidance on various aspects of vehicle maintenance, repair, and troubleshooting, ensuring that owners can keep their STS running smoothly and reliably for years to come.