MS42 EWS Delete
MS42 EWS Delete
BMW Performance / MS42 Tuning
Fits: E36 · E46 · E39 · Z3
Overview
This is a custom binary flash for the Siemens MS42 ECU that permanently removes the EWS (Elektronische Wegfahrsperre) immobilizer loop from the DME. The ECU will start and run any M52TU engine without needing a matched EWS module, ring antenna, or key transponder.
Common use cases include standalone/swap builds, EWS module failure, damaged or lost keys, and track cars where a matching EWS system is impractical. All other ECU calibrations — fueling, ignition timing, VANOS, and emissions — remain stock and unmodified unless otherwise specified.
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
- Custom
.binflash file matched to your ECU hardware number (HW #) and software number (SW #) - EWS loop removed — no EWS module, ring antenna, or key transponder required to start
- Stock fueling, ignition timing, and VANOS calibration preserved
- Flashing instructions + recommended tool list (WinKFP, NCS Expert, or compatible JTAG/BDM flasher)
- Email support for flashing questions
How to order
- Select your displacement variant (2.5L or 2.8L) and add to cart
- After purchase, reply to your order confirmation email with your ECU's hardware number (HW #) and software number (SW #) — found on the ECU label or via INPA / DIS
- Receive your custom
.binfile via email — typically within 1 business day - Flash using WinKFP, NCS Expert, or a compatible JTAG/BDM flasher
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 file for an M54 application — see our MS43 EWS delete listing instead.
Shipping & mail-in service
This listing also supports a mail-in flashing service for customers who don't have access to flashing hardware. Ship us your ECU, we flash it and ship it back — typically a 2–3 business day turnaround from the day we receive it.
- Purchase this listing and select the Mail-In Flash variant at checkout
- Reply to your order confirmation with your ECU's HW # and SW # (from the ECU label or INPA)
- Pack your ECU securely and ship it to the address provided in your confirmation email — we recommend a padded box, not an envelope
- We flash, verify, and ship your ECU back via USPS Priority Mail (2–3 days transit) with tracking
- 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 |
Packing tip: Remove the ECU from the car before shipping. Wrap it in bubble wrap and place it in a rigid box with padding on all sides. Do not ship in a plastic bag or padded envelope — ECUs have fragile connector pins.
Off-road / motorsport use only. This file is intended for vehicles not operated on public roads, including track cars, engine swap builds, and motorsport applications. Buyer is responsible for verifying compliance with all applicable local regulations before use.
This is a digital product — no returns or refunds once the file has been delivered. Have a question before purchasing? Contact us.