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P2504 is a diagnostic trouble code (DTC) for "Charging System Voltage High". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.
The P2504 OBD-II fault code simply means that an irregularity was detected in the charging system circuit - specifically that the voltage was high. This high voltage reading may have originated from the battery, charging system, or starter.
The P2504 trouble code means that a higher than normal voltage within the charging system was detected. The code alone, however, does not indicate whether this high reading is an intermittent or ongoing issue.
Most commonly caused by a faulty alternator or other charging system issue, the PCM detects a voltage higher than the accepted parameters, registers the P2504 code, and then illuminates the Check Engine Light on the vehicle’s dashboard.
Aside from the illumination of the Check Engine Light, a vehicle registering the P2504 code may also display one or more of the following symptoms:
Using a specialized scan tool with a greater sensitivity and scope of application than those found in auto parts stores, a mechanic can verify the existence of the P2504 code. Using the information collected and provided by that scan tool, the mechanic can then use professional reference materials to interpret that data and determine a probable cause for the trouble code registering.
The technician then performs a hands-on inspection of the affected system and most likely culprits, replacing any worn components or making other needed repairs. Afterwards, the mechanic may test drive the vehicle and use the scan tool again to verify that the issue has been resolved.
The most frequent mistakes a mechanic may make within a P2504 trouble code diagnosis are:
Not verifying the existence of the P2504 code
Failing to test the alternator and unnecessarily replacing the battery or starter
Failing to thoroughly inspect the alternator, battery and related charging system components
Forgetting to clear the P2504 OBD-II fault code after making needed repairs
Since the P2504 code registers due to voltage abnormalities in the alternator, battery, or charging system, the problem can worsen over time, ultimately preventing a vehicle from starting or staying running. If the issue is left neglected, such voltage spikes may affect other components or systems, resulting in more costly repairs down the road.
After the validation of the P2504 code by a qualified mechanic in possession of a specialized scan tool, the following repair(s) may be required:
Since there are multiple potential causes of the P2504 code registering, it can take up to several hours for a qualified mechanic to accurately diagnose the cause of the fault code. Multiple scans and other tests may be in order even after repairs have been made to verify the issue has been satisfactorily resolved.
Let YourMechanic connect you with an experienced and qualified mechanic to diagnose and repair the cause of the P2504 code in your vehicle. If needed, that technician can even come to you at your home or office for your convenience and safety. Receive a quote, book an appointment with a mechanic online or talk with a service advisor at 1-800-701-6230.