P2503Charging System Voltage Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- How the car detects it
- P2503 means the charging output is below target: with the engine running the module expects the generator to lift system voltage, but it stays too low. FCA calls the code Charging System Output Low. On the 2020 Dodge Durango its technical centre linked P2503 or P2504 with a lit battery lamp and no-start to a loose B+ stud on the feed from alternator to power distribution centre, or to a failed alternator pulley that turns freely both ways. A 2021 Ram 1500 case shows P2503 stored together with P2504 and a lit check engine lamp, traced by voltage-drop testing of the wiring. Unlike P0562, which reports a low supply at the module itself, P2503 judges the charging output. Expect a dim, weakening battery and possibly a stall or no-start.
- What you may notice
- Battery lamp and check engine lamp on
- Dim lights, electrical consumers dropping out
- Engine stalls or will not start
- Likely causes
- LikelyLoose or burnt B+ connection between alternator and fuse box
- LikelyWorn alternator (brushes, diodes, regulator)
- PossibleFailed overrunning pulley or slipping belt
- RarePoor engine or chassis ground
- Repair
- Medium · Often possible to do yourself.Typical cost: €40 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.