BMW 3 Series E90 E91 E92 325D M57N2 Diesel Manual Engine Wiring Loom Harness

BMW 3 Series E90 E91 E92 325D M57N2 Diesel Manual Engine Wiring Loom Harness is a factory-spec wiring set designed for the precise connection of all key sensors, actuators, and control units within the powertrain. It is responsible for stable power supply and signal transmission in the diesel engine, ensuring the proper operation of the drivetrain. Thanks to its design tailored to specific body and drivetrain versions, it serves as a reliable service solution for repairs or wiring harness swaps.

Specifications and technical data

• SKU: rhd-7802567-1
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7801103
• Substitutable numbers: 12517802567, 7802567, 12517796073, 7796073, 12517801103, 7801103
• Fuel type: Diesel
• Gearbox type: Manual
• Category: Wiring Harnesses, Cables & Connectors

Purpose and compatibility

This engine wiring harness has been designed specifically for BMW 3 Series E90, E91, and E92 325D models with the M57N2 engine. The layout of the wires, connectors, and mounting points is adapted to the diesel engine's auxiliary equipment and the engine bay configuration of these generations.

The component is intended for use with a diesel engine and a manual transmission, which is crucial for matching connectors to sensors and modules related to the drivetrain. This allows the harness to maintain the factory wiring logic and minimizes the risk of installation errors.

Construction and technical function

The engine wiring harness belongs to the Cables, looms, and connectors category, responsible for the electrical integration of components in the engine bay. The set includes multi-core wires with various cross-sections and dedicated connectors for sensors, injectors, control elements, and electronic modules.

Key functions of this harness include:

• transmitting measurement signals from sensors to the engine control unit (ECU),
• powering actuators within the powertrain,
• ensuring proper communication between the engine and other vehicle systems,
• maintaining organized wire routing in the engine bay.

Thanks to its factory fitment for the specific BMW model, the harness helps maintain electrical system consistency and facilitates future diagnostics.

Service application and installation

The presented harness is particularly useful for:

• repairing damaged engine wiring (burns, abrasions, connector corrosion),
• replacing the powertrain within the same generation and engine version,
• restoring the original electrical configuration after previous modifications.

As a BMW component, the harness retains the original geometry, section lengths, and connector placement, which promotes installation in accordance with service documentation. This facilitates the mechanic's work and limits the need for wiring modifications.

Condition and benefits of choosing a used part

The offered engine wiring harness is in Used condition, meaning it has been removed from a vehicle and was previously in operation. Such components are frequently chosen by professional workshops as an economical solution that remains consistent with the manufacturer's factory specifications.

Using an original, used harness allows for maintaining compatibility with factory equipment and avoiding problems typical of universal aftermarket replacements. It is a practical solution for repairs where compliance with the vehicle's electrical system and the stable operation of a diesel engine with a manual transmission are critical.

Expanding the BMW electrical system

If you are planning a comprehensive repair or upgrade of the engine area in your BMW and need other components from the same group, such as additional looms, sensor wires, or module connectors, check out the available parts in the BMW cables, looms, and connectors category.

For users interested in a broader context of modifying and upgrading MINI vehicles, including the use of used components, the article describing the characteristics of sports versions and the possibilities of upgrading standard models may be helpful: MINI John Cooper Works – what makes it stand out and how to upgrade your MINI?.