Decode SPN 110 (engine coolant temperature)¶
Goal¶
Extract engine coolant temperature samples from a J1939 capture using the SPN-aware decoder, with no DBC file required.
Prerequisites¶
- CANarchy installed.
- Any J1939 capture. The examples use
tests/fixtures/j1939_heavy_vehicle.candump.
Run¶
canarchy j1939 spn 110 \
--file tests/fixtures/j1939_heavy_vehicle.candump \
--text
Expected output (abridged):
spn: 110
file: tests/fixtures/j1939_heavy_vehicle.candump
observations:
- spn=110 name=Engine Coolant Temperature value=85.0 units=degC pgn=65262 sa=0x31 da=broadcast
- spn=110 name=Engine Coolant Temperature value=86.0 units=degC pgn=65262 sa=0x31 da=broadcast
- spn=110 name=Engine Coolant Temperature value=87.0 units=degC pgn=65262 sa=0x31 da=broadcast
JSONL for downstream tools¶
canarchy j1939 spn 110 \
--file tests/fixtures/j1939_heavy_vehicle.candump \
--jsonl \
| jq '[.spn, .value, .units, .timestamp]'
Other useful SPNs¶
| SPN | Description |
|---|---|
| 190 | Engine speed |
| 84 | Wheel-based vehicle speed |
| 96 | Fuel level |
| 100 | Engine oil pressure |
Pass any of them to canarchy j1939 spn <id> --file ….