P2504Charging System Voltage High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- How the car detects it
- P2504 is logged when the charging output overshoots: the measured voltage rises above what the module asked the generator to produce. FCA names it Charging System Output High and publishes several cases. A 2021 Ram 1500 lit the check engine lamp after a repair, with P2504 set and P2503 stored, and the advice was to voltage-drop every circuit involved. On a 2022 Ram 1500 that would not crank, the cause was the N1 connection at the high-current fuse array plus poor grounds from battery to body and from body to engine. The Durango bulletin treats P2504 alongside P2503 and the loose B+ post. Poor connections fool the measurement, so a sound alternator can be blamed. P0563 differs: it rates the module supply. Real overcharging can boil the battery and damage electronics.
- What you may notice
- Check engine lamp, sometimes battery lamp
- Very bright lights, bulbs failing early
- No crank in connection-related cases
- Likely causes
- LikelyHigh resistance at B+ fuse array or ground straps distorting the reading
- PossibleRegulator stuck and overcharging
- RareBattery current or voltage sensor delivering wrong values
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.