After charge battery,malfunction indicater lamp is on

P2500 Generator Lamp/L-Terminal Circ Low

Indicator

This code indicates that a fault has been detected in the generator lamp control circuit. The PCM may have also detected an abnormal voltage reading from the vehicle battery, starting, or charging system.

Code Set Parameters

In the event of generator lamp control circuit fault, a trouble code will be stored and a service engine soon lamp will be illuminated. Some models require multiple drive cycles (as many as 8) with a failure in order for the service engine soon lamp to be illuminated and others will activate it on the initial failure.

Symptoms

This code indicates that a fault has been detected in the charging system circuit. The PCM may have also detected an abnormal voltage reading from the vehicle battery, starting, or charging system.

Common Causes

The most common cause of this code can be traced to a faulty alternator. Other causes could include a bad battery or starter, open or shorted wiring or battery cables, insufficient battery primary or secondary grounds, defective voltage regulator, corroded battery terminal ends, a faulty PCM (rare), a large battery drain, or a defective battery.

Common Misdiagnosis

Technicians report that batteries and starters are often replaced in error when the alternator is either not charging or overcharging. If the battery is discharged, charge it and test the vehicle charging system to make sure that it is operating properly.

Diagnosis

• The starting/charging system is monitored by the PCM whenever the key is placed in the "ON" position, as is the generator lamp circuit for the instrument panel
• When the engine is running, the PCM is programmed to anticipate between 13.8 and 14.4 volts from the charging system
• If a voltage reading that either exceeds or underachieves, a code will be stored and a service engine soon lamp illuminated
• Some vehicle models (especially Chrysler) also use the PCM to regulate charging system voltage
• System voltage malfunctions related to the PCM are much more common in vehicles equipped with this type of system than in other systems. Before beginning your diagnosis, make sure that the battery is fully charged
• If the battery fails to take or hold a charge, it should be replaced. Several tools will be instrumental in successfully diagnosing this code
• A suitable OBD-II scanner (or code reader) and a digital volt/ohmmeter will be most helpful in performing a successful diagnosis
• Begin with a visual inspection of all wiring and connectors
• Repair or replace damaged, disconnected, shorted, or corroded wiring, connectors, and components as necessary
• Always retest the system after repairs are completed to ensure success. If all system wiring, connectors, and components (Including fuses) appear to be in normal working order, connect the scanner (or code reader) to the diagnostic connector and record all stored codes and freeze frame data
• This information can be extremely helpful in diagnosing intermittent conditions that may have contributed to this code being stored
• Continue by clearing the code and operating the vehicle to see if it returns
• This will help to determine whether or not the malfunction is intermittent
• After the codes are cleared, test drive the vehicle to see if the code returns
• If the code fails to immediately return, you may have an intermittent condition
• Intermittent conditions can prove to be quite a challenge to diagnose and in extreme cases may have to be allowed to worsen before a correct diagnosis can be made
• Continue with a visual inspection of the battery and battery cables
• Should you find excessive corrosion on the battery terminals, suspect a poor battery connection
• If this is the case, disconnect the battery cables from the battery (always disconnect the ground cable first and see manufacturer's recommendations for disconnecting/reconnecting the battery) and remove the corrosion from the battery posts and terminals
• Reconnect the battery and retest the charging system
• Connect the starting/charging system tester to the battery and perform a load test
• If the battery fails the load test, replace it
• If the battery passes the load test, leave the tester connected and start the engine
• Observe the voltage readings on the tester and compare your findings with manufacturer's specifications
• Replace starting/charging system components as required
• Typical alternator output should read approximately 14 volts with the engine started and no accessories or lighting turned on
• Leave the tester connected and use the amp probe to test the starter current draw
• Compare your findings to manufacturer's specs and repair or replace starting system cables or other components as needed. The generator lamp circuit is used to activate a charging system indicator in the instrument panel if system voltage is abnormal
• Voltage readings that are too low may indicate worn brushes in the alternator
• High voltage readings may be indicative of a defective voltage regulator (usually integrated in the alternator but some are part of the PCM)
• Before performing any continuity and resistance testing on the generator lamp circuit, be sure to disconnect the wiring from the instrument panel to prevent damage to system controllers and circuit boards
• Consult the vehicle service manual for reference voltage readings and other precautions. If the starting/charging system are in proper working order, you will need to test secondary wiring
• Disconnect the alternator connector and test all circuits using the digital volt/ohmmeter
• If alternator wiring values are in line with acceptable specifications, disconnect the PCM connector and perform a continuity test on all system circuits
• Compare actual findings with manufacturer's specifications and repair open or shorted electrical wiring as necessary. If the malfunction has still not been rectified, suspect a defective PCM.

With the battery light being on indicates the alternator is not charging . That can cause other electrical issues . Take to an auto parts store an they will test it for you. or take it to a ASE certified repair shop .

There is a problem somewhere in the system, have it scanned with a scan tool and see what is going on. Parts stores usually have them to loan out.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/michael_2496c4f07ad24453

If the battery is the original battery then it's 6 years old. Try and put a charge on it for a couple of hours and if it doesn't crank the engine then I'd pull the battery and take it to an auto parts store. Have them load test it. It's probably bad.

i would suspect the alternator brushes are worn out or the commutator worn out

take it to the auto parts store they will check the charging system for free

Your factory alarm is sensing the low voltage, and it assumes someone is trying to tamper with the battery. If you can't reset your alarm shortly after the jumper leads are attached, your battery is more than likely unable to hold a charge. Have a local autoparts store check your battery with a load meter to see if it is "dead".
You will want to do this asap since your car is more than likely running off the alternator, and it will fail very quickly if you continue to drive the vehicle.

Hi, you'll need to get the engine light codes read. Most auto parts stores do it for free, or you could buy a code reader. You need those trouble codes to figure out what and where the problem lies. You can look up the codes here: http://www.check-engine-light.com

I am posting a generic reply to the "charge fail" lamp (that is the correct term - when the lamp is lit = the battery is NOT being charged) problems rather than a specific cure for the ills in your car.

I suspect a faulty alternator OR an inadvertent short to battery - potential of the wire leading from the charge fail lamp to the battery charging alternator. Please try the following tests (BE CAREFUL while working - you are working near the engine + v belts + fans etc. and a fully charged battery = can be very dangerous)

Locate the three terminals of the battery charging alternator. The largest terminal would be connected to the battery positive cable (may be red in colour). The second terminal could be labeled as "W" = this is the terminal generating a frequency proportional to the engine speed for the tachometer. The third terminal is the WL or D terminal. The Charge Fail lamp is connected from battery positive (via the ignition switch) to this WL/D terminal.

Turn the ignition switch on but don't start the engine. Observe the "Charge Fail" lamp glowing in the dashboard. Now remove the wire going to the WL/D terminal. The "Charge Fail" lamp should now stop glowing. If the lamp continues to glow, there is surely a shortcircuit between the wire from the lamp to the alternator.

As this lamp current is not going to the WL/D terminal due to the short circuit, the battery charging alternator is not producing very little or no output. Check if the battery terminal voltage rises when the engine is running. If the alternator is working correctly, the battery would be at 13.2 Volts with the engine running.

The confirmatory test is to rig a spare lamp (12V, 3 or 5 watt lamp in a holder) between battery + to the WL/D terminal - if that works properly (lit when the engine is stopped and off when the engine ir running), you can connect a new wire from the lamp to the WL/D terminal - do isolate the earlier wire completely from from lamp as well as alternator end.
Hope this helps. Write back if I have confused you further.....

Apurva from Pune, India.

Looks like you have earthing problems. I would check earth connection for indicators. renew if necessary.