Standards context
Standards context: FMI terminology in SAE J1939 / J1587
Standards context, not OEM truth
This page paraphrases a small amount of terminology from the cited standards. It does not assign a meaning to any code or archive row. The printed label on each row remains the authority for that row.
The FMI is the second number in an SPN/FMI pair. This page explains the general role the cited standards give that number, then stops. It is separate from the observed-values hub and from every OEM label table.
Standards context only · No archive codes are interpreted here · Report a correction
What this page is
This is the one page on the site where standards terminology is paraphrased. It is not a decoder, a diagnostic guide, or a statement about a specific machine. It does not reproduce the full standards table. It covers only the general structure needed to read the phrase “SPN/FMI pair.”
The cited documents are SAE J1939 / J1587, published by SAE International. This site is independent of SAE International. The paraphrase here is not a substitute for the published documents.
Why the FMI is the second number
An SPN/FMI pair has two positions. The SPN identifies the parameter a controller watches. The FMI identifies the failure mode reported for that parameter. In the cited standards terminology, the FMI is the second of the two numbers.
The pair is an identifier, not an instruction. The same FMI can sit beside different SPNs, and each OEM row carries its own printed label. The archive keeps that label with the row; this page does not translate it.
A paraphrase of the minimum
SAE J1939 / J1587 describe a range of failure modes for the FMI position. In the cited standards context, FMI 3 is described as a voltage-above-normal condition. That sentence is a paraphrase, not a quotation.
The full standards table is not reproduced here. This page does not map a value to an OEM label, and it does not say that any row in the archive has the condition described by the standards. A standards description and an OEM printed label are different kinds of text, and the archive keeps them separate.
What this page does not do
- It does not assign a meaning to any SPN/FMI pair.
- It does not rank values by importance or likelihood.
- It does not identify a component, a cause, or an operating limit.
- It does not replace the printed label or the source manual.
Citation
Citation: SAE International, SAE J1939 / J1587. The FMI terminology summarized on this page is drawn from those documents. They are not reproduced or distributed here.
The archive's data sources, collection method, and correction process are described on the methodology page. For the observed values and their counts, use the FMI reference. For the printed labels attached to a specific key, use the code index.