Control module voltage
Last reviewed 2026-08-31
Mode 01 · PID 42 (decimal 66)
Description
Control-module / OBD supply voltage. On a hybrid this is not HV pack voltage.
- PID number
- 42 · 66
- Unit
- V
- Range
- 0 … 65.535
- Data bytes
- 2
- Formula
- ((A*256)+B)/1000
- 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.
Signals that use this PID
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 Mode 01 public formula