MS42 DME Reset (Virginization)

BMW Performance / MS42 Tuning

Fits: E36  ·  E46  ·  E39  ·  Z3

Overview

This is a VIN/ISN binding clear and re-write service for the Siemens MS42 ECU. We virginize the ECU — clearing all existing VIN and ISN data — then write your vehicle's VIN directly to the unit, allowing it to pair cleanly with your car's EWS system.

Common use cases include used ECU swaps, replacement units with unknown ISN history, and builds where the original ECU has been lost or damaged. All other ECU calibrations — fueling, ignition timing, VANOS, and emissions — remain stock and unmodified.

Compatibility

Engine	BMW M52TUB25 / M52TUB28
ECU	Siemens MS42 only
Market	US / Canada spec
Chassis	E36, E46, E39, Z3
Displacement variants	2.5L — M52TUB25  |  2.8L — M52TUB28

What's included

• VIN/ISN binding cleared — ECU virginized to a blank state
• Your VIN written to the ECU — ready to sync with your existing EWS system
• Stock fueling, ignition timing, and VANOS calibration preserved
• Email support for questions

How to order

1. Select your displacement variant (2.5L or 2.8L) and add to cart
2. After purchase, reply to your order confirmation email with your vehicle VIN
3. Mail your ECU to the address provided in your confirmation email

Identifying your ECU

MS42 is used exclusively on the M52TU engine — the M52TUB25 (E46 323i, E39 523i, Z3 2.5) and M52TUB28 (E46 328i, E39 528i, Z3 2.8). If you're unsure whether your car runs an MS42, verify via INPA or check the ECU part number — MS42 part numbers begin with 7 526 xxx or 7 527 xxx.

Note: The M54 engine uses the MS43 ECU, not MS42. Do not order this service for an M54 application — see our MS43 listings instead.

Shipping & mail-in service

This listing is a mail-in service. Ship us your ECU, we virginize and re-write your VIN, then ship it back — typically a 2–3 business day turnaround from the day we receive it.

1. Pack your ECU securely and ship it to the address provided in your confirmation email — we recommend a padded box, not an envelope
2. We virginize, write your VIN, verify, and ship your ECU back via USPS Priority Mail (2–3 days transit) with tracking
3. Return shipping is included in the service price

Turnaround time	2–3 business days from receipt
Return shipping	Included — USPS Priority Mail with tracking
Inbound shipping	Customer's responsibility — insure your ECU, they are not cheap
Accepted carriers	USPS, UPS, FedEx — no preference

This is a programming service — no returns or refunds once the ECU has been flashed and returned. Have a question before purchasing? Contact us.