What is a Cummins ECFG file?
A Cummins ECFG is the XML definition Calterm needs to read a calibration: each parameter's name, address, type and scaling. What it is, how to pick one.
- ECFG = Engineering Tool Config File: the Cummins XML that tells Calterm what every byte of a calibration means.
- It is matched to a calibration by two header fields: product id (e.g.
BKR) and software / calibration version (e.g.64.60.21.5). - It is the Cummins equivalent of a DAMOS or A2L. Without it, a .xcal read is just hex.
- The archive holds 1,119 ECFG and 681 E2M files across 207 product ids and 23 ECM platforms.
The one-line answerWhat is inside oneWhy the product id and version matterWhat you can do with itECFG, E2M and .xcal in one sentence eachWhich one do I need?
The one-line answer
An ECFG (Engineering Tool Config File) is the definition file Cummins Calterm loads before it can show you a calibration. The calibration itself (the .xcal you read out of the ECM, or the data in flash) is a block of binary values. The ECFG is the dictionary: for each parameter it gives the name (C_TRQ_Max_Trq_Lmt, T_SFD_..., A_ATM_... and so on), the ITN (the Cummins parameter identifier), the data type, byte length, scaling factor and offset, engineering units, min/max limits, and the description Cummins engineers wrote for it. Tables and axes are described the same way with their dimensions.
If you come from Bosch or Continental ECUs: it is the Cummins DAMOS / A2L. If you come from GM or Ford: it is the definition XML your editor loads. Same job, Cummins format.
What is inside one
An ECFG is plain XML, typically 10 to 25 MB, and opens in any text editor. The first lines are the identity:
| Header field | Example | Meaning |
|---|---|---|
Engineering_Tool_Config_File version | 64.60.21.5 | the calibration / software version this ECFG describes |
calibration_version | 64.60.21.5 | same value, repeated inside the compatibility header |
module_name | CM24xx | ECM hardware family (CM2250, CM2350A, CM2450B ...) |
product_id | BKR | three-letter dataset code: the engine program / market |
index_table_address | 0x00842000 | where the ECM's parameter index table sits in flash |
byte_order | BigEndian | all CM-series Cummins ECMs are big-endian |
interface_level / boot loader range | 4.6.0.0, 2.4.2.0 to 2.4.3.4 | which Calterm interface and ECM boot loaders the file was built for |
crc | 04A6 | 16-bit header check |
After the header come tens of thousands of <parameter> records. A CM2450 X15 ECFG in the archive has around 32,000 named parameters; a CM2350A industrial one about 24,000; a 2003-era CM850 file far fewer. Every ECFG page on this site shows the real header of the file you would receive plus a sample of its parameters grouped by area (torque, fuelling, boost, EGR, DPF, SCR, speed limits, fault codes).
Why the product id and version matter
Calterm will only pair an ECFG with a calibration when the product id and calibration version match, because ITN addresses move between builds. So the first thing to do with any Cummins job is to read those two values. They are in the .xcal header, in Calterm's connect dialog and (as the ECM code and software phase) in INSITE. Our guide on finding the product id and software version walks through each place.
A few practical rules we have confirmed across the archive:
- Parameter names are stable within a product id. If your exact version is missing, the neighbouring version of the same product id resolves almost every parameter, and the product id page lists every version we hold.
- The same calibration version can ship under two product ids (for example
BEEandBEG32.0.13.2 on CM2350A Tier 4 Final industrial engines are the identical calibration). We note these pairs where we know them. - Module naming in the header is a family (
CM23xx,CM24xx), not the exact board. The ECM generations guide maps families to the engines and years they cover.
What you can do with it
With the right ECFG and a read of the calibration you can open the file in Calterm, or have the ECFG converted into a WinOLS map pack so every table lands at its real address, named, scaled and foldered (see WinOLS and DAMOS for Cummins). Typical reasons people buy one:
- Diagnose a problem calibration-side: see the actual thresholds behind a derate, a fault-code enable, a soot model, a DEF dosing limit.
- Compare two calibrations of the same product id (a 450 hp and a 500 hp rating, an OEM file against a Cummins baseline).
- Build or audit a tuning file: torque curves, rail pressure, boost, VGT, speed limiter, idle shutdown, and the emission-system tables a DPF / EGR / SCR file service edits.
- Research: parameter dictionaries for a platform you are reverse-engineering.
ECFG, E2M and .xcal in one sentence each
ECFG is the modern XML definition (CM850 onward). E2M is the older text-format definition used for Celect, CM550/CM570 and other pre-2007 ECMs; we hold 681 of them (see ECFG vs E2M). .xcal is the calibration itself, the Calterm read or write file, not a definition (see what is an .xcal).
Which one do I need?
- Read the product id and software version from your calibration or from the truck.
- Search the pair on the home page. An exact hit shows the file's header; the product id page shows every neighbouring version.
- If nothing is close, send us the
.xcalheader: we can usually synthesise an ECFG for an exact build from a neighbouring version of the same product id, and we can convert any ECFG to WinOLS or A2L.
Coverage today: 1,119 ECFG files, 681 legacy E2M files, 207 product ids, 98 engine families, dated 2000 to 2026. The biggest groups are CM2350 (448 files), CM2250 (191) and CM2450 (112).
Frequently asked questions
Is an ECFG the same as a DAMOS or A2L?
Functionally yes. DAMOS and A2L describe Bosch and Continental calibrations; the ECFG describes a Cummins calibration. All three give each parameter a name, address, type, scaling and limits. An ECFG can be converted to a WinOLS map pack or an A2L.
Does the ECFG contain the calibration values?
No. It contains definitions only. The values live in the .xcal (or in the ECM flash). You need both: the calibration read and the ECFG that matches its product id and version.
My version is not in the archive. Is a neighbouring version safe?
For reading and naming, usually yes: names are stable within a product id and most ITNs resolve. For writing, confirm the handful of parameters you are changing against the real file, or ask us to synthesise an exact-build ECFG.
How big is an ECFG and what opens it?
10 to 25 MB of XML. Calterm loads it natively; any text editor or XML parser can read it; we can deliver the same definition as WinOLS OLSX or A2L.
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.