P2502 - CHARGING SYSTEM VOLTAGE

Vehicle charging systems consist of the alternator, a regulator that is often located inside the alternator, and interconnecting cables. This system maintains the charge in the vehicle’s battery and carries the main source of electrical power while the engine is running. If the charging system is not working properly, the battery can be discharged quickly. If there is a “dead battery” condition and an improperly functioning alternator, the engine will stop running.

Setting the P2505 OBDII diagnostic code indicates that the battery voltage has been below 10V for more than 8 seconds so the Check Engine light will turn on.

• MIL (Malfunction Indicator Lamp) light ON.
• The engine stops at idle.
• You may notice a decrease in fuel efficiency.

Reasons to set the P2502 OBD2 error code:

• Perhaps the alternator is defective.
• Cables related to the vehicle's charging system may have defects.
• The vehicle's battery may be in bad condition.

Steps to solve the DTC P2502 OBDII code:

• Check all the cables leading to the vehicle's charging system, repair or replace any of these components that are torn or burned.
• Check the battery terminals and check for corrosion. If excessive corrosion is found, remove it.
• Check the current battery charge level. If it is low, perform a battery load test. If this test fails, replace the battery.
• Check the alternator output voltage. Generally, an alternator reads 14 volts with the engine running with no lights or accessories on. Compare the results with the manufacturer's specifications. If the result is below the indicated voltage, it shows that there is wear on one of the alternator's brushes.
• On the other hand, if the reading is above the specifications, it indicates that the voltage regulator is faulty. Replace it.
• Perform continuity and resistance tests on the alternator lamp circuit. Consult reference voltage readings. Repair wiring if there are inconsistencies between actual and expected values.