Mercedes-Benz GL-Class GL 320 CDI, GL 450, GL 550 Operator's Manual (P/N 164 584 74 81)

• Covers 2008 Mercedes-Benz GL-Class GL 320 CDI, GL 450, and GL 550 variants, providing exact operational baselines for vehicle controls and safety systems
• Official OEM publication Part No. 164 584 74 81, Edition A 2008, delivered as a comprehensive 601-page PDF
• Contains detailed exploded-view diagrams of the cockpit and overhead controls, streamlining diagnostic and repair planning
• This 2008 edition serves as the definitive reference for the launch build, documenting specific operation for the 164-series architecture before mid-cycle changes
• Explains KEYLESS-GO, Tele Aid, Parktronic, 4-ETS, and COMAND
• Details TPMS, air suspension, ADS, and Voice Control

Vehicle Systems and Operation Reference

The 2008 Mercedes-Benz GL-Class operator's manual offers a thorough walkthrough of vehicle systems and safety protocols essential for daily workshop operations. Technicians can directly reference the exact factory-intended operation of the cockpit, instrument cluster, and center console to expedite troubleshooting. This includes deep-dives into variants equipped with or without the enhanced off-road package. Additional sections meticulously define the use of the climate control system, lighting switches, and advanced driving systems such as Distronic and Downhill Speed Regulation (DSR). Understanding these baseline functionalities is a critical prerequisite before beginning any complex repair or diagnostic procedure. Always verify factory safety protocols regarding high-voltage systems and supplemental restraints prior to interacting with vehicle electronics to prevent accidental deployment or injury.

Component Identification and Technical Data

This guide delivers extensive technical descriptions regarding the occupant classification system, side impact and window curtain air bags, and seat belt restraint requirements. To support mechanical and electrical work, the text incorporates specific poly-V-belt drive layouts, fuse allocation charts, instrument cluster views, and tire inflation pressure tables. You will find precise reference tables for starter switch positions, gear selector lever usage, and windshield wiper operations documented throughout the text. Furthermore, the manual provides specific operating constraints regarding the use of LATCH-type child seat anchors and the function of the override switches for rear door windows.

For independent mechanics and DIYers, the document provides crucial step-by-step instructions that typically require an expensive dealership visit. These include manually resetting triggered active head restraints, properly synchronizing power windows and the tilt/sliding sunroof after a voltage drop, safely replacing halogen bulbs, bleeding the diesel fuel system, and executing an emergency engine shut-down via the fuse box. When servicing the X164 platform, professionals must navigate specific repair traps. For instance, accessing the main VRLA battery requires precisely cutting the perforated floor carpet under the passenger seat; if the battery is completely dead, the vehicle must be jump-started first just to operate the power seat rails. Additionally, on the GL 320 CDI, allowing the fuel tank to run dry necessitates a strict ignition cycling procedure to bleed the lines, as cranking a dry system will quickly destroy the high-pressure diesel pump. By supplying official documentation of the GL-Class controls, this manual establishes a factual baseline to verify customer complaints against normal vehicle operation, drastically cutting down unbillable diagnostic time in the service bay.