Mercedes Vito W639 Ignition Switch Lock Control Module Unit A6399008100

Visual condition of the part

The product shows signs of use visible in the photos.

Mercedes Vito W639 Ignition Switch Lock Control Module Unit is an original part from the Ignition Accessories group, designed for the starting system in the W639 generation Vito model. This solution allows for the restoration of proper ignition switch operation, ensuring correct integration with the vehicle's electrical system and comfortable ignition handling.

Specifications and technical data

• SKU: A6399008100
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6399008100
• Substitutable numbers: A6399008100, A 639 900 81 00
• Category: Ignition Modules

Purpose and function in the ignition system

The ignition switch in the Mercedes-Benz Vito W639 is responsible for performing key functions in the ignition circuit – from unlocking the steering column and powering the onboard electrical system to engaging the starter. A correctly selected component from this group allows for stable ignition switching, reduces the risk of power interruptions, and supports trouble-free engine starting.

As a part from the Ignition Accessories category, the presented ignition switch is a crucial component in the vehicle's electrical control area – its efficiency affects the operation of many systems dependent on the key position (dashboard power, accessories, safety systems).

Benefits of using an original Mercedes ignition switch

Using an original solution dedicated to the Vito W639 ensures compatibility with the factory electrical installation and steering column design. As a result:

• proper cooperation with the wiring harness and control modules is maintained,
• the risk of starting problems resulting from improper part fitment is reduced,
• the ergonomics of key operation and predictable ignition switch positions are preserved.

For the user, this means more reliable vehicle starting, consistency with factory security features, and easier diagnostics of potential faults in the future. Choosing a component prepared specifically for the Mercedes brand also helps maintain the integrity of the entire ignition system.

Characteristics of the used component

The presented ignition switch is a used part, which in practice offers a favorable compromise between cost and functionality. This type of part allows for an economical repair of the ignition system while maintaining the original design and fitment for the Vito W639. A used component can be a good choice when the priority is to quickly restore vehicle functionality within a controlled service budget.

For installation, it is recommended that the work be performed by an experienced service center, which will ensure proper seating of the ignition switch, correct connection of the terminals, and verification of all key positions after installation.

Application in service practice

The Mercedes-Benz Vito W639 ignition switch will prove useful both for typical replacement of a worn-out part and for repairs following mechanical damage to the steering column or problems with ignition engagement. It can be used as a replacement part in vehicles used intensively – e.g., in delivery transport, where the reliability of the starting system has a direct impact on fleet operational continuity.

If you are planning a comprehensive repair or upgrade of the ignition system area in your Mercedes and need other elements from the same group, such as ignition lock cylinders, steering lock elements, or additional control components, check the available parts in the Mercedes Ignition Accessories category.

Additional technical support

For broader service work, including the drivetrain, guide materials regarding the selection and operation of components may be helpful. In the context of planning repairs related to the drivetrain, it is worth reading the article Transmission: manual, automatic or DSG – typical faults and a guide to buying a used gearbox, which facilitates making informed service decisions.