OBD-II code · Powertrain (generic, extended)
P2504 Charging System Voltage High
The ECU detects a battery voltage above the regulated upper limit. The voltage regulator is not limiting alternator output, risking damage to electronic modules and battery overcharge.
Is it safe to drive with P2504?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyFaulty voltage regulator
- PossiblePoor alternator ground
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–3 h
- Emissions test
- Usually unaffected
- Parts involved
- Alternator, Voltage Regulator, Battery
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.