2008 Mercedes-Benz R-Class Operator's Manual (P/N 251 584 39 81)

• Covers the 2008 Mercedes-Benz R-Class in four factory-listed configurations: R 320 CDI 4MATIC (251.122, diesel engine 642), R 350 (251.156) and R 350 4MATIC (251.165, gasoline engine 272), and R 550 4MATIC (251.172, gasoline engine 273). This edition identifies the R 350 as USA-only and the R 550 4MATIC as Canada-only in its engine-data tables.
• Official Mercedes-Benz 569-page Operator's Manual PDF, Part No. 251 584 39 81, Order No. 6515 1817 13, Edition A 2008; it is not dealer workshop service literature.
• Maps the cockpit, instrument cluster, multifunction steering wheel, center console, exterior lighting, and control-system menus, with operating sequences for SmartKey, KEYLESS-GO, the automatic transmission, and Limp-Home Mode.
• Explains SRS and Occupant Classification System (OCS) logic together with seat-belt, active-head-restraint, child-restraint, ABS, BAS, ESP, EBP, immobilizer, and anti-theft functions.
• Details available equipment such as AIRMATIC, 4MATIC, Distronic, Parktronic, rear-view camera, Tele Aid, power tailgate, 3-zone automatic climate control, and rear climate-control arrangements, while clearly marking optional and market-specific features.
• Provides illustrated owner-level procedures for window and roof synchronization, active-head-restraint reset, SmartKey-battery, wiper-blade, and owner-serviceable bulb replacement, spare-wheel mounting, diesel fuel-system bleeding, vehicle-battery removal and reconnection, jump starting, towing-eye installation, fuse access, and emergency engine shutdown.
• Includes warning-lamp and multifunction-display troubleshooting tables, model-specific poly-V-belt layouts, tire and loading guidance, and factory specifications for engines, electrical systems, rims and tires, dimensions, weights, capacities, fuels, coolants, and lubricants.

Vehicle Systems and Operation Logic

This is the factory Operator's Manual supplied for the covered 2008 R-Class models. Mercedes-Benz wrote it for the vehicle operator, so it is best suited to owners and drivers who need exact control logic, warning interpretation, routine checks, and roadside procedures. Technicians can also use it to confirm equipment behavior and vehicle-specific operating requirements before diagnosis or repair. It is not a workshop repair manual.

The control chapters go well beyond a basic switch directory. They show how starter-switch and KEYLESS-GO states interact with starting and locking, how transmission ranges and steering-wheel gear selection behave, and what Limp-Home Mode changes. Separate sections cover the standard climate-control arrangement and the 3-zone automatic system, including rear controls, defrosting, recirculation, and residual heat. Driver-assistance coverage distinguishes equipment that may not be installed on every vehicle, including the Canada-only Distronic and distance-warning functions described in this edition.

Practical Procedures, Diagnostics, and Repair Boundaries

The Practical Hints chapter pairs instrument-cluster lamps and multifunction-display messages with possible causes, consequences, and the appropriate operator response. It addresses restraint-system faults, brake and stability warnings, AIRMATIC messages, coolant and engine-oil alerts, battery and charging faults, lighting failures, tire-pressure monitoring, transmission messages, and SmartKey or KEYLESS-GO problems. The emergency material then covers access to the vehicle tool kit, manual unlocking, fuel-filler release, lamp and wiper service, flat-tire work, battery handling, jump starting, towing, and fuse-box locations.

Two cautions show why the factory instructions matter before repair work begins. The collapsible spare requires its dedicated wheel bolts; using the road-wheel bolts can physically damage the brakes. The side-impact sensors are located in the doors, so improper door or trim repair can disable the side airbags or cause unintended deployment. The manual also reserves Bi-Xenon lamp work and SRS work for qualified technicians because of the high-voltage and deployment hazards involved.

Illustrations, Specifications, and Scope

Illustrated references include cockpit and instrument-cluster layouts, center and overhead control-panel maps, front and rear lamp locations, the three fuse-box locations, engine-specific poly-V-belt routing, and spare-wheel/towing-eye views. The Technical Data section identifies each 251-series type and supplies model-specific engine, electrical, wheel-and-tire, dimensional, weight, and fluid-reference tables without turning the manual into a component overhaul guide.

Scheduled service requirements remain in the separate Maintenance Booklet. Circuit-specific fuse allocation is on the fuse chart stored with the vehicle tool kit, and COMAND, Voice Control, and some optional equipment use separate instructions. This PDF does not contain full wiring schematics, diagnostic trouble-code test plans, engine or transmission disassembly, module coding, or dealer-level repair procedures.