P25FFElectrical System Voltage Stabilizer Control Module Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- How the car detects it
- P25FF reports that the module which steadies the 12 V supply for sensitive electronics does not work as intended. Such stabilizers mainly appear on cars with automatic engine stop/start: every restart drags the battery voltage down hard, according to a semiconductor maker briefly below 4 V, which would otherwise reset radios, displays and similar loads. A DC/DC stage raises the voltage for those moments. No manufacturer publicly documents P25FF itself. GM's 2017 Chevrolet Malibu illustrates the circuit in practice: current fed back through the OnStar backup battery wiring into the DC-DC converter inhibited stop/start and lit the MIL, cured by removing a single fuse, without a code being named. Usually stop/start stays disabled and screens may reboot on restart; the engine keeps running normally.
- What you may notice
- Automatic stop/start no longer active
- Radio or display resets when the engine restarts
- Warning light depending on the maker
- Likely causes
- LikelyInternal fault in the voltage stabilizer or DC/DC converter module
- PossibleAged or wrong-type 12 V battery so the module cannot hold the voltage
- RareCurrent backfeed or poor supply/ground connection at the module
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.