Run time since engine start
Last reviewed 2026-08-31
Mode 01 · PID 1F (decimal 31)
Description
Seconds the engine has been running this cycle.
- PID number
- 1F · 31
- Unit
- s
- Range
- 0 … 65535
- Data bytes
- 2
- Formula
- (A*256)+B
- Also valid as Mode 02 freeze-frame data (same PID number, snapshot at last DTC).
Defined by SAE J1979 / ISO 15031-5. Public index — not a substitute for the paid SAE document.
Sources
Provenance for this page. Official standards outrank community notes. See the confidence policy.
Official standard · high trust
SAE J1979 / ISO 15031-5 Mode 01 PID formulas (public index)
J1979 public PID index: 01 1F