Overview

This is a ready-made bench harness for the Siemens MS42 and MS43 ECU. It breaks out all necessary connectors to power and flash the ECU on the bench — fully outside the vehicle. No splicing, no fabrication required.

Designed for anyone doing ECU programming, ISN/VIN work, or flashing on a used unit before install. Works with a standard 12V bench supply or car battery and is compatible with common MS42/MS43 flashing tools.

Compatibility

Engine	BMW M52TU / M54B25 / M54B30
ECU	Siemens MS42 & MS43
Chassis	E36, E46, E39, E60, X3, X5, Z3, Z4

What's included

Pre-built bench harness with MS42/MS43 ECU connector(s)
Pinout reference and bench setup instructions

How to use

Plug the harness into your MS42 or MS43 ECU
Connect the power leads to a 12V bench supply
Connect your flashing tool and flash as normal — no vehicle required

Shipping

Fulfillment	Ships within 1–3 business days
Carrier	USPS Priority Mail with tracking
Ships from	United States

Have a question before purchasing? Contact us.

BMW Modifications / ECU Tools & Hardware

Fits: E36 · E46 · E39 · X3 · X5 · Z3