ECFG vs E2M: which Cummins definition file do you need?
E2M is the older text-format Cummins definition (Celect, CM550, CM570); ECFG is the XML format for CM850 to CM3230. How to tell them apart.
- E2M = older INI-style text definition for Celect / Celect Plus, CM550, CM552/554, CM570, CM800 and early CM850 calibrations.
- ECFG = XML definition for every Core-II ECM from CM850 through CM871, CM2150, CM2250, CM2350, CM2450, CM2670, CM2880 and CM3230.
- Both carry a product id and a calibration version; both are what Calterm needs to decode a read.
- The archive holds 681 E2M files and 1,119 ECFG files.
Two generations of the same ideaHow to tell which you haveWhat stays the sameDifferences that bite in practiceWhich do you buy?
Two generations of the same idea
Cummins has always shipped a definition file alongside each calibration so the engineering tool can name parameters. The format changed once, around the Core-II software generation (2003 to 2007 depending on the engine). Before that, definitions were E2M files; after it, ECFG XML. If you work on anything from an N14 Celect Plus to a 2006 ISX CM870 you will meet E2M; anything with a DPF will be ECFG.
| E2M | ECFG | |
|---|---|---|
| Format | text, INI-like sections [Header Records] / [Data Records] | XML, <Engineering_Tool_Config_File> root |
| Era | 1990s to about 2007 | 2003 (CM850 Core-II) to current |
| ECMs | Celect, Celect Plus (N14, M11), CM550 (ISB VP44), CM552 / CM554 (ISC / ISL CAPS), CM570 (ISX / ISM Signature), CM800, CM870 ISX EGR, early CM850 | CM850 Core-II, CM871 / CM876, CM2100, CM2150, CM2200, CM2250, CM2350A/B, CM2450A/B/E, CM2620A, CM2670A/F, CM2880A, CM3230A/B |
| Identity fields | CalibrationVersion, ProductID, ModulePN, MarketID, EngineID, FileDescriptor | version, calibration_version, module_name, product_id, index_table_address, byte_order, interface_level |
| Typical size | 0.5 to 3 MB | 10 to 25 MB |
| Parameters | a few thousand | 20,000 to 32,000 |
| Tool | Calterm (legacy modules), INSITE for service functions | Calterm, INSITE |
| In the archive | 681 files, E2M legacy page | 1,119 files, complete index |
How to tell which you have
Open the definition in a text editor. An E2M starts with a [Header Records] block and lines such as CalibrationVersion= and ProductID=. An ECFG starts with an XML declaration and <Engineering_Tool_Config_File version="...">. On the truck side: if INSITE shows a calibration with a DPF, SCR or a CM2xxx module, it is ECFG territory. Celect Plus, Signature 600, ISX CM570 and the VP44 / CAPS midrange are E2M.
The archive's E2M files cover product ids and families such as CELECT-PLUS, CENTRY, ISB (5.9 VP44 Dodge Ram), ISC / ISL CAPS, ISM, ISX Signature, QSK19 / QSK60, QSB / QSC, and gas (GAS, C-GAS-PLUS). Browse them on the N14 / M11 Celect Plus, ISB 5.9 VP44, ISX Signature / EGR and QSK / QST pages.
What stays the same
Both formats are keyed by product id plus calibration version, both describe every parameter with an address, type and scaling, and both are what a WinOLS map pack is generated from. The workflow in the ECFG guide applies to both: identify the pair, find it (or the nearest version of the same product id), then open the calibration in Calterm or convert the definition to WinOLS.
Differences that bite in practice
- Legacy module reads. E2M-era ECMs are read with older adapters and Calterm versions, and some (CM570, CM870) were also handled by INSITE calibration downloads rather than full image reads. If you are planning a read, see reading and flashing a Cummins ECM.
- No emission aftertreatment tables. Pre-2007 calibrations have no DPF, SCR or DEF tables, so the file services that matter there are power ratings, speed limiter, derates and fault codes, not deletes.
- Parameter counts. E2M calibrations are small; a Celect Plus definition has a fraction of the content of a CM2350 ECFG. That also makes them quick to convert to WinOLS.
- Pricing. Legacy E2M files are priced lower than modern ECFGs; each file page shows its price.
Which do you buy?
Match the format to the ECM, not to the engine name. An "ISB 5.9" can be a 1998 VP44 CM550 (E2M) or a 2005 common-rail CM850 (ECFG). An "ISX" can be Signature CM570 (E2M), CM870 EGR (E2M) or CM871 EPA07 (ECFG). The ECM generations table lists which module each engine and year used, and every file page on this site states its format next to the price.
Frequently asked questions
Can Calterm open an E2M?
Yes, Calterm supports legacy E2M definitions for the older modules; the current Calterm releases still load them alongside ECFG XML. INSITE never shows either format directly; it uses its own calibration packages.
Can an E2M be converted to WinOLS like an ECFG?
Yes. It carries addresses, types and scaling, so the same conversion to an OLSX map pack applies, with fewer maps because the calibrations are smaller.
Is there an E2M for a CM2250 or CM2350?
No. Everything from CM850 Core-II onward is ECFG. If someone offers you an E2M for a DPF-era engine it is for a different module.
What does 'E2M-ECFG-LATEST' or 'OLDER-E2M' mean in your index?
Those are folder-level product ids from the legacy archive where the file header did not record a clean product id. Open the file page to see the calibration version and descriptor it carries.
Related guides
Guides are written from the archive and from work on real calibrations; they describe what the ECM does and what the services are. Emission-related file work is for off-road, export, racing and research use only.