P2500 - GENERATOR LAMP / L - TERMINAL CIRCUIT LOW

When the DTC P2500 OBDII code is stored, it means that the car’s computer found a lower-than-expected voltage signal in the generator lamp or alternator control circuit. The letter “L” in this code refers to the lamp control circuit.

The generator lamp belongs to the instrument panel. It warns the driver of possible charging system problems once it is illuminated. The continuity of its circuit is monitored by the PCM (Powertrain Control Module) when the vehicle is running.

The generator lamp control circuit is very important to the generator operation. Besides that, it maintains the battery charge levels.

• Check Engine light illuminated.
• Charging system lamp illuminated.
• The engine has drivability problems.
• The engine shuts down accidentally.
• Delays during engine start.

Reasons to set the P2500 OBD2 fault code are:

• Perhaps the generator field control circuit is open or shorted.
• The system may have a blown fuse or fuse link.
• The generator could be faulty.

To troubleshoot the P2500 OBDII diagnostic code, try this:

• Check the vehicle's information source to know the Technical Service Bulletins that are available.
• Check that the battery charge level is suitable for the system to work properly. If it is not, charge it.
• Check the warning lamp circuit for battery voltage. If this is not the case, check the system fuses and relays. Repair or replace as necessary.
• If battery voltage is present in the circuit, make sure the lamp bulb is not burned out.
• Check the wiring and connectors related to the alternator circuit. Check that there is a good ground connection. Make corrections as necessary.