Engine oil gallery pressure. On J1939 this is a scaled PGN parameter, on OBD a mode-01 PID, and on a telematics REST feed usually already converted — to one of four different pressure units. The canonical form is bar; psi, kPa and the rest are converted on the way in.
vehicle.engine.oil_pressureEach of these is a real tag as the device or controller emits it, taken from the Forge mapping corpus. This is the table that does not exist anywhere else — the reason cross-vendor telemetry is hard is visible in a single column.
| OEM / profile | Raw tag as the device emits it | Confidence |
|---|---|---|
| Caterpillar | SPN_100 | 1.00 |
| Cummins | SPN_100 | 1.00 |
| Detroit Diesel | SPN_100 | 1.00 |
| Freightliner | SPN_100 | 1.00 |
| John Deere | SPN_100 | 1.00 |
| Kenworth | SPN_100 | 1.00 |
| Mack Trucks | SPN_100 | 1.00 |
| Navistar / International | SPN_100 | 1.00 |
| PACCAR | SPN_100 | 1.00 |
| Peterbilt | SPN_100 | 1.00 |
| Volvo Trucks | SPN_100 | 1.00 |
Every row above is an exact match — a deterministic pack entry or a confirmed corpus mapping — so all of them carry confidence 1.00. That is not a rounding: these are the two exact-match layers, and a tag that resolves here never reaches the embedding or LLM layers. Mappings resolved by the LLM layer do carry sub-1.0 confidence, but those are per-tenant and are not published here.
The canonical field is not just a name. It is a contract about units, sign convention and plausible range, enforced on the way in and re-checked at read time.
| SI / canonical unit | bar |
| Accepted input units | MPa Pa atm bar inHg kPa mbar mmHg psi |
| Converted on ingest | MPa Pa atm inHg kPa mbar mmHg psi → bar |
| Physics bounds | 0 to 1000000 bar |
| Measurement type | instantaneous |
| Distinct source tags in the corpus | 7 |
No mapping table to maintain, and no per-vendor branch in your code. The same request shape works for every OEM in the table above.
Read alongside this one.
vehicle.engine.oil_temp vehicle.turbocharger.rpm vehicle.dtc_description spindle_speed_rpm spindle_load_pct