Xenon Module Audi A3 8P A4 B7 Headlamp Headlight Ballast Control Unit 8P0907391

The Audi A3 8P / A4 B7 Headlight Xenon Module is an original part from the Ballasts and Ignitors for Lamps category, designed to control and power xenon lamps in the front headlights. It ensures stable operation of the lighting system, proper ignitor ignition, and maintenance of adequate light output on both the left and right sides.

Specifications and technical data

• SKU: 8P0907391
• Mark: Audi
• Condition: Used
• OEM Part Number: 8P0907391
• Substitutable numbers: 8P0907391, 8P0 907 391, 8E0941329A, 8E0 941 329 A, 1307329154
• Location on the vehicle: Front, Left, Right
• Category: Headlight Ballasts & Ignitors

Application and Function in the Lighting System

The presented xenon module is a factory headlight controller responsible for the control of the xenon lamp's operation in the front of the vehicle. It works with the car's electrical system, processing control signals and delivering appropriately shaped voltage to the ignitor, which translates into stable, uniform road illumination.

Thanks to its dedicated design for specific Audi models, the module maintains full compatibility with the factory lighting system, including onboard diagnostics. Proper placement in the front headlight on the left or right side allows for safe installation without altering the lamp's structure.

Compatibility and Fit for Audi

As an Audi brand component, the module has been designed for precise fitting into headlights used in A3 8P and A4 B7 models equipped with xenon lighting. This means:

• maintaining the original mounting geometry in the lamp,
• compatibility with the factory wiring harness,
• correct communication with the vehicle's electronics.

The availability of interchangeable part numbers in the technical specifications facilitates the selection of the appropriate controller for different headlight equipment versions within a given model year.

Condition, Verification, and Benefits of Choosing a Used Module

The offered module is a used original part, which in practice means retaining factory quality of workmanship while reducing the cost of lighting system repairs. Compared to low-quality aftermarket alternatives, an original controller ensures better compatibility with the vehicle's installation and a lower risk of diagnostic errors.

Choosing a verified used module is particularly beneficial when:

• the xenon headlight has stopped working or operates unstably,
• there are intermittent light outages on one side of the vehicle,
• diagnostics indicate a faulty lamp controller.

Installation and Technical Aspects

The module is designed for installation in the front of the vehicle, on the left or right side, according to the headlight's construction. Installation involves mechanically securing the controller in the lamp and connecting it to the factory wiring harness, which preserves the original lighting system architecture. Installation by a person experienced with high-voltage systems in xenon headlights is recommended.

A correctly selected and installed module restores full headlight functionality, improving driving safety after dark and ensuring uniform, homologation-compliant road illumination.

Related Products and Technical Knowledge

If you need other components from the ballasts and ignitors category designed for this brand's vehicles, for example, for a comprehensive xenon lighting system repair, check the available parts in the Audi Ballasts and Ignitors for Lamps category.

When planning electrical system repairs, it is also worth considering the condition of the vehicle's charging system; in this context, a guide describing when it is worthwhile to opt for used parts, such as a practical article on replacing an alternator with a used one, may be helpful.