🏷️ Basic Information

Make:

Cadillac

Model:

STS

Year:

2006

Generation:

Second Generation (2005-2011)

Platform:

GM Sigma

👋 Introduction

Positioning:

The 2006 Cadillac STS was positioned as a luxury performance sedan, competing in a segment dominated by European and Japanese rivals. It aimed to blend American luxury with sporty driving dynamics, a departure from some of Cadillac's earlier models.

Competitors:

Key competitors for the 2006 Cadillac STS included the BMW 5 Series, Mercedes-Benz E-Class, Audi A6, Lexus GS, and Infiniti M35/M45.

Distinctive Features:

The 2006 STS was noted for its available all-wheel-drive, Magnetic Ride Control suspension, and powerful Northstar V8 engine options, aiming to deliver a refined yet engaging driving experience.

Value Proposition:

This service and repair manual is an invaluable resource for STS owners and independent mechanics, providing direct access to the same factory-specific, step-by-step instructions, diagrams, and wiring schematics used by dealership technicians. It empowers users to perform maintenance, diagnostics, and repairs with accuracy and confidence, reducing reliance on expensive dealership labor and generic online information.

📋 Manual Details

Coverage:

All models and all repairs A-Z

Page Count Estimate:

Extensive (typical factory service manuals for this era can range from 2,000 to 4,000+ pages depending on engine/drivetrain variants)

Type:

Factory Service Manual / Repair Manual

Language:

English

Format:

PDF

📖 Manual Coverage

Engine:

Detailed coverage including: Engine mechanical, control systems, fuel service, emission control, intake/exhaust, cooling, lubrication, ignition, starting, and charging systems.

Powertrain:

Comprehensive coverage of automatic transmissions, manual transmissions (if applicable to specific trims), transfer cases, propeller shafts, drive shafts, differentials, and axles.

Chassis:

Includes: Suspension, steering column, power steering, brakes (control, hydraulic, parking), tires, and wheels.

Body And Interior:

Covers: Air conditioning, supplemental restraint system (SRS), seat belts, engine immobilizer, cruise control, wipers and washers, door locks, meters, audio/visual systems, horns, windshield/glass/mirrors, instrument panel, seats, engine hood/doors, exterior and interior trim, and glass.

Electrical And Electronics:

Extensive coverage of electrical system diagnostics, wiring schematics, multiplex/CAN communication systems, and various electronic modules.

Climate Control:

Detailed coverage of the automatic climate control system, including AC system diagnosis, refrigerant handling, component testing, and HVAC blower motor and control module information.

Maintenance:

Complete step-by-step instructions for scheduled maintenance, fluid checks and changes, filter replacements, and general upkeep.

Diagnostics And Troubleshooting:

Detailed diagnostic procedures, symptom-based troubleshooting guides, fault code identification, and electrical system diagnostics.

Repair And Rebuild:

Comprehensive repair procedures for all major components and systems, including engine rebuilds, transmission overhauls, brake system repairs, suspension component replacement, and bodywork.

Installation And Adjustment:

Instructions for component installation, calibration, and adjustment of various systems.

Body And Frame:

Covers body panel alignment, door repairs, glass replacement, bumper repairs, and basic structural information.

Depth:

Factory-level technical depth, suitable for professional technicians and advanced DIY enthusiasts. Includes detailed schematics, torque specifications, diagnostic flowcharts, and specialized tool requirements.

Wiring Schematics:

Includes complete and detailed wiring schematics for all electrical systems, crucial for diagnosing electrical faults and understanding component interconnections.

📊 Manual Specifications

File Format:

PDF

Print Quality:

High quality, printable pages with clear illustrations and diagrams. Ability to zoom and enlarge images for detailed viewing.

Binding Type:

N/A (Digital PDF format)

Paper Type:

N/A (Digital PDF format - printable on any paper type)

Operating Systems:

Compatible with Windows (Vista 32/64, XP, ME, 98, NT, 2000) and Mac operating systems.

Software Requirements:

Adobe PDF Reader and WinZip (or equivalent unzipping software) are required, both of which are free to download online.

⚙️ Engine Specifications

Engine Options:

The 2006 Cadillac STS was offered with two primary engine options: a 3.6L V6 and a 4.6L Northstar V8. This manual will cover both.

3.6L V6 Specs:

3.6L DOHC V6 (LLT or LY7 depending on market/specifics), producing approximately 255-275 horsepower and 250-260 lb-ft of torque.

4.6L V8 Specs:

4.6L DOHC Northstar V8 (LD8 or LH2), producing approximately 320-325 horsepower and 295-300 lb-ft of torque.

Fuel Delivery:

Multi-port fuel injection (MPI) for both V6 and V8 engines, with detailed specifications for fuel pressure, injector flow rates, and fuel pump diagnostics.

Coolant Type:

Specific coolant type (likely Dex-Cool or equivalent orange silicate-free coolant) and capacity will be detailed in the manual, along with testing and bleeding procedures.

Oil Type Capacity:

Manual will specify SAE viscosity grade (e.g., 5W-30) and API service classification (e.g., API SM or SN) for engine oil, along with correct oil capacity for each engine variant.

🔧 Transmission

Transmission Type:

The 2006 STS primarily featured a Hydra-Matic 5L50-E 5-speed automatic transmission. Manual transmissions were not offered on this model in most markets.

Drivetrain:

Available in Rear-Wheel Drive (RWD) and All-Wheel Drive (AWD) configurations.

Transmission Features:

The 5L50-E transmission is known for its adaptive shifting logic and manual shift mode. The manual will cover diagnostic procedures, fluid type (likely DEXRON VI or equivalent), capacity, and service intervals.

📐 Dimensions

Wheelbase:

Approximately 116.4 inches (2957 mm)

Length:

Approximately 196.3 inches (4986 mm)

Width:

Approximately 72.7 inches (1847 mm)

Height:

Approximately 57.5 inches (1461 mm)

Curb Weight Estimate:

Ranging from approximately 3,800 to 4,100 lbs (1724 to 1860 kg) depending on engine and drivetrain.

Trunk Volume:

Approximately 15.3 cubic feet (433 liters)

🛡️ Safety Features

NHTSA Front Impact:

Generally good ratings, often 4 or 5 stars for front driver and passenger in NHTSA crash tests.

IIHS Frontal Offset:

Often received 'Good' ratings from the IIHS in frontal offset crash tests.

Electronic Stability Control:

Standard StabiliTrak electronic stability control system.

Anti Lock Brakes:

Standard Anti-lock Braking System (ABS) with brake assist.

Traction Control:

Standard traction control system.

Airbags:

Standard front airbags, front side-impact airbags, and curtain side airbags. The manual will detail SRS system diagnostics and replacement procedures.

Seat Belts:

3-point active seatbelts with pretensioners and load limiters for all seating positions.

💡 Technology Features

Infotainment System:

The 2006 STS typically featured Cadillac's infotainment system with a central display, navigation options, premium audio systems (e.g., Bose), and CD changer.

Adaptive Cruise Control:

Optional adaptive cruise control system, which automatically adjusts vehicle speed to maintain a set distance from the vehicle ahead.

Magnetic Ride Control:

Standard or optional Magnetic Ride Control (MRC) suspension system, which uses magnetorheological fluid to instantly adjust damping based on road conditions and driving inputs. The manual covers MRC diagnostics and calibration.

Telematics:

OnStar telematics system was likely available, providing services such as emergency assistance, vehicle diagnostics, and turn-by-turn navigation. The manual will cover related system components.

Headlights:

High-intensity discharge (HID) Xenon headlights were often standard or optional, along with automatic headlamp leveling. The manual will detail their operation and maintenance.

🔧 Maintenance

Oil Change Interval:

Typically based on oil life monitoring system or every 7,500 to 10,000 miles, with specific recommendations in the manual for severe driving conditions.

Tire Rotation:

Recommended every 7,500 miles. The manual will detail proper procedure and torque specifications for lug nuts.

Transmission Fluid Change:

Often listed as 'lifetime' by some manufacturers, but professional recommendations suggest fluid and filter changes every 60,000 to 100,000 miles. The manual will provide specific guidance and fluid type.

Brake Fluid:

DOT 3 or DOT 4 automotive brake fluid, depending on system requirements. Manual will specify exact type and procedure for flushing and bleeding.

Power Steering Fluid:

Specific power steering fluid type will be listed. Use of incorrect fluid can damage the system.

Coolant Type:

GM specified orange silicate-free long-life coolant (e.g., Dex-Cool). Manual will provide correct type, mixture, and capacity.

Common Wear Items:

Common wear items for vehicles of this era and class may include front suspension components (bushings, ball joints), wheel bearings, oxygen sensors, and ignition coils. The manual's diagnostic section is crucial for identifying these.

Northstar Engine Considerations:

While robust, older Northstar engines could be prone to coolant leaks from intake manifold gaskets or head gasket issues if not properly maintained. This manual will provide specific diagnostic procedures for cooling system integrity.

📚 Vehicle History

Cadillac Legacy:

Cadillac, founded in 1902, is America's longest-producing automobile manufacturer. It has historically represented American luxury, prestige, and technological innovation, often introducing advanced features to the automotive market.

Sts Lineage:

The STS (Seville Touring Sedan) nameplate built upon the legacy of the Seville, a vehicle that marked Cadillac's return to a more European-influenced, sport-oriented luxury sedan. The second generation STS, introduced for the 2005 model year, was a significant redesign built on the GM Sigma platform, emphasizing performance and advanced technology.

Manufacturing Location:

The 2006 Cadillac STS was primarily manufactured at the GM Assembly Center in Lansing, Michigan, USA.

🏆 Awards & Recognition

Automotive Press Reviews:

The 2006 STS received generally positive reviews from automotive journalists for its handling, comfortable ride, and advanced technology features for its time, though some critiques focused on interior design or powertrain refinement compared to some European competitors.