Ram DT 2025+ • US↔EU conversion / market coding

Ram DT 2025+ US to EU conversion via configuration (market coding)

Market coding is a controlled set of configuration edits that change how the vehicle behaves in a different region (units, region options, feature flags, and other market-level parameters). FCA PROXI Tool works configuration-first: you edit only what you need, keep the original Configuration Code, and generate checksum-correct output so the vehicle accepts the edited buffer.

Related: if you are here because a scan tool mentions “proxy / PROXI alignment”, start with the Ram DT 2025+ PROXI page: Ram DT 2025+ PROXI Alignment guide.

Access note: on some vehicles, write operations may require an authorized diagnostic session (SGW). See: Ram DT 2025+ SGW access & requirements.

Common requests

What “US→EU conversion” usually includes

Units / cluster behavior (mph↔km/h where applicable), language and region settings.
Market-level option flags (regional behavior differences).
Infotainment / cluster region-related parameters.
Certain lighting and feature behavior flags where supported by equipment (varies by build).

Exact options depend on model year, trim, and installed modules.

Key idea

Keep the Configuration Code

In many Ram DT 2025+ conversion edits, the safest path is preserving the original Configuration Code and changing only the required bytes/bits. FCA PROXI Tool recalculates CRC/checksums using proprietary logic so the vehicle accepts the edited buffer without forcing a full alignment routine in typical scenarios.

Workflow

Targeted writes (not “flash everything”)

Backup the original exported configuration buffer unchanged.
Edit bytes/bits with Standard / Advanced / PROXI Map Editor.
Save checksum-correct output (CRC/checksums recalculated).
Write only to the ECUs that require the change, then validate behavior.

Compliance

Do it responsibly

Regional coding may affect lighting or safety-related behaviors. Always follow your local regulations and workshop safety policy. This page is technical documentation, not legal advice.

Conversion vs PROXI alignment

“Proxy alignment” is often used as a general term for configuration mismatch. For market conversion jobs, focus on the configuration edits first. Alignment/sync routines are separate distribution steps that may be required only in specific situations.

Conversion

Edit what you need

Change the smallest set of bytes/bits required for the requested market behavior. Document every change.

Consistency

Checksum-correct output

After edits, the buffer must remain internally consistent. FCA PROXI Tool generates checksum-correct output so the vehicle accepts the change.

Targeted write

Write to selected ECUs

In many cases you can write only to the ECUs that require the change while preserving the original Configuration Code to reduce mismatch risk.

Recommended workflow (Ram DT 2025+ conversion)

A conservative process that reduces rework and avoids unnecessary platform-wide sync steps.

Backup: save the original exported configuration buffer unchanged.
Define the target: list the exact market behaviors you need (units/region/options).
Edit with intent: change only required bytes/bits. Avoid “big rewrites”.
Save correct output: ensure CRC/checksums are recalculated.
Write back: write only to the ECUs that require the change, then verify behavior.
Sync only if required: run an alignment/sync step only if the platform insists after a correct write.

What we need from you

To keep changes safe and predictable, don’t start from guesses.

Inputs

Minimum required

VIN + model year / trim.
Original configuration buffer backup (untouched).
Clear list of requested market behaviors.

Nice to have

Helps confirm correctness

Module list / scan report (what ECUs are present).
Current region settings if known.
Any restrictions you hit (SGW/access messages).

If write actions are blocked, review access requirements first: Ram DT 2025+ SGW access & requirements.

FAQ

Do I need a full PROXI alignment after market coding?

Not always. For many conversion edits, preserving the original Configuration Code and using checksum-correct output helps avoid mismatch states. Run a sync routine only if the platform requires it after a correct write.

Can I write only to selected ECUs?

Yes, in many cases. FCA PROXI Tool workflows are designed around targeted writes to the ECUs that actually need the change.

What does “US→EU conversion” usually include on Ram DT (2025+)?

Typical requests include region/units and market flags, infotainment region parameters, cluster behavior, and other market-level option bytes. Exact options depend on trim, modules, and model year.

Do 2025+ DT trucks require authorized access for writes?

Sometimes. Newer platforms may restrict write operations. If your write is blocked or rejected, use an authorized workflow suitable for your region and tools.

Is this legal?

Regional coding can affect lighting or safety-related behaviors. Always follow local regulations and workshop safety policy. This documentation is not legal advice.