Vehicle Segment:
Full-size Luxury Sedan
Brand Prestige:
Represents Mercedes-Benz's flagship luxury offering of the era
Key Competitors:
BMW 7 Series, Lexus LS, Audi A8, Jaguar XJ
Engineering Focus:
Emphasis on comfort, build quality, advanced technology, and refinement
Manual Value Proposition:
Provides the authoritative, factory-level information necessary for proper maintenance and repair of a complex luxury vehicle
Coverage Scope:
Comprehensive service, repair, maintenance, diagnostics, and troubleshooting
Manual Classification:
Factory Service Manual / Repair Manual
Digital Format:
PDF (implied, common for digital versions of such manuals)
Powertrain:
Engine mechanical, fuel system, ignition system, cooling system, exhaust system, emissions control
Transmission:
Automatic transmission (722.6 '5G-Tronic')
Chassis:
Suspension (front/rear), steering system, braking system (ABS, ESP), drive shafts, axles
Electrical:
Engine control module (ECM), body control module (BCM), lighting, power accessories, comfort systems, multiplexed systems
Body And Interior:
Body panels, doors, windows, seats, HVAC, interior trim, sound insulation
Diagnostics And Troubleshooting:
Fault code retrieval, diagnostic procedures, component testing, electrical troubleshooting charts
Maintenance Procedures:
Oil change, filter replacement, fluid checks and changes, spark plug replacement, belt inspection/replacement
Repair Procedures:
Engine overhaul, transmission overhaul, suspension component replacement, brake caliper/rotor replacement, electrical component repair
Diagnostic Procedures:
Component testing, system checks, symptom-based troubleshooting guides
Wiring Schematics:
Complete electrical circuit diagrams for all vehicle systems
Part Layouts:
Exploded views of components and assemblies
Depth Of Coverage:
Detailed diagnostic procedures, component-level repair, advanced system diagnostics, specifications for all repair operations
Torque Specifications:
Precise torque values for all fasteners and critical components
Special Tools:
Identification and usage of Mercedes-Benz specific tools required for repairs
Digital Searchability:
Searchable text (if PDF), indexed sections
Print Clarity:
High-quality reproductions of original factory documentation
Binding:
Professional perfect binding or ring-bound for lay-flat use (typical for workshop manuals)
Paper Quality:
Durable, high-gloss paper suitable for workshop environments
Engine Type:
3.2L Inline-6, DOHC, 24-valve
Horsepower Approximate:
228 hp @ 5500 rpm
Torque Approximate:
232 lb-ft @ 3750 rpm
Fuel Injection:
Bosch Motronic M3.1 (Electronic Fuel Injection and Ignition)
Fuel Type:
Premium Unleaded Gasoline (91 octane or higher)
Bore X Stroke:
89.9 mm x 84.0 mm
Compression Ratio:
10.0:1
Coolant Type:
Mercedes-Benz approved coolant (e.g., G48 or equivalent) mixed 50/50 with distilled water
Transmission Type:
5-speed Automatic (722.6 '5G-Tronic')
Transmission Control:
Electronic control with limp-home mode
Gear Ratios:
Specific ratios detailed within the manual (e.g., 1st: 3.93, 2nd: 2.43, 3rd: 1.41, 4th: 1.00, 5th: 0.73)
Transmission Fluid Type:
ATF MB 236.8 (e.g., Mobil ATF 220, Shell Spirax S4 ATF 3403)
Transmission Fluid Capacity:
Approximately 9.0 liters (including torque converter drain)
Crash Test Data:
While official NHTSA ratings for this specific year are scarce, the W140 was designed with significant safety features for its era.
Traction Control:
ASR (Anti-Slip Regulation), often a precursor to modern ESP
Braking System:
ABS (Anti-lock Braking System), Brake Assist (BAS)
Airbags:
Driver and front passenger airbags
Seatbelts:
Pretensioning front seatbelts
Body Construction:
High-strength steel safety cage, crumple zones
Audio System:
Factory premium sound system (often Becker or Bose), with CD changer option
Navigation:
Optional Becker or Bosch navigation system (early generation, often map-based)
Cruise Control:
Standard electronic cruise control
Parking Assistance:
Optional Parking Assist (APS) sensors, front and rear (introduced on later W140 models)
Telephony:
Optional integrated car phone system
Climate Control:
Dual-zone automatic climate control (THERMOTRONIC)
Seating:
Electrically adjustable front seats with memory, optional heated and ventilated seats
Oil Change Interval:
Typically every 10,000-15,000 km (6,000-9,000 miles) or annually, refer to manual for specific conditions.
Transmission Fluid Change Interval:
Recommended every 60,000-100,000 km (36,000-60,000 miles), subject to driving conditions. Early 722.6 transmissions had specific initial break-in procedures. Consult manual for exact service A/B schedules.
Coolant Flush Interval:
Every 2-3 years or 50,000 km (30,000 miles)
Engine Oil Specification:
MB 229.1 or MB 229.3 (e.g., 0W-40, 5W-40, 5W-30 synthetic oil depending on climate)
Engine Oil Capacity:
Approximately 7.5 liters (7.9 US quarts) with filter change
Power Steering Fluid:
MB 343.0 or MB 236.3 (e.g., Pentosin CHF 11S or equivalent)
Common Problems W140:
Cooling system leaks (hoses, water pump, radiator), SRS warning light (seat occupancy sensor, wiring harness), window regulator failures, vacuum actuator failures (central locking, climate control), biodegrading wiring insulation (older models), MAF sensor issues, catalytic converter failure. The manual will detail troubleshooting for these.
Transmission 722.6 Considerations:
Conductor plate failures, torque converter issues, early software glitches. The manual will guide diagnosis and repair for these.
Manufacturer Legacy:
Mercedes-Benz, renowned for engineering excellence and luxury automotive production since 1926.
W140 Generation:
Second generation of the S-Class, introduced in 1991, succeeding the W126. Known for its substantial size and technological advancements.
1996 Updates:
The 1996 model year saw the introduction of the 5-speed 722.6 automatic transmission ('5G-Tronic'), a significant upgrade for refinement and efficiency.
Production Period:
1991-1998 (W140 generation)
Manufacturing Location:
Germany
