I just when and got my battery recharged to 100 percent. could i still have a bad cell in the battery.

Question edited for clarity, full 'year make model'.
Question moved to the correct category.

Jeff has the answer Up there ^^ and now here.

• Jeff Armer
• Apr 21, 2022
• You need to hook up a professional grade scan tool to check codes in all the computers (modules) in the vehicle . That vehicle has a smart charging system , amp sensor around the battery negative cable. lets the computers know how much current is being used so it knows how much to put back , suppose to help battery last longer . Look that up on the internet ,watch youtube videos .
  https://www.youtube.com/watch?v=xN7SIHgA...
  https://ricksfreeautorepairadvice.com/gm...
• 
  Jeff Armer
• Apr 21, 2022
  SERVICE BATTERY CHARGING SYSTEM
  The BCM and the ECM will send a GMLAN message to the DIC for the SERVICE BATTERY CHARGING SYSTEM message to be displayed. It is commanded ON when a charging system DTC is a current DTC. The message is turned OFF when the conditions for clearing the DTC have been met.
  
  
  DTC - diagnostic trouble codes
  
  Generator
  The generator is a serviceable component. If there is a diagnosed failure of the generator it must be replaced as an assembly. The engine drive belt drives the generator. When the rotor is spun it induces an alternating current (AC) into the stator windings. The AC voltage is then sent through a series of diodes for rectification. The rectified voltage has been converted into a direct current (DC) for use by the vehicles electrical system to maintain electrical loads and the battery charge. The voltage regulator integral to the generator controls the output of the generator. It is not serviceable. The voltage regulator controls the amount of current provided to the rotor. If the generator has field control circuit failure, the generator defaults to an output voltage of 13.8 volts.
  
  Body Control Module (BCM)
  The body control module (BCM) is a GLAN device. It communicates with the engine control module (ECM) and the instrument panel cluster (IPC) for electrical power management (EPM) operation. The BCM determines the output of the generator and sends the information to the ECM for control of the generator turn on signal circuit. It monitors the generator field duty cycle signal circuit information sent from the ECM for control of the generator. It monitors a battery current sensor, the battery positive voltage circuit, and estimated battery temperature to determine battery state of charge (SOC). The BCM performs idle boost.
  
  Battery Current Sensor
  The battery current sensor is a serviceable component that is connected to the battery cable at the battery. The battery current sensor is a 3-wire hall effect current sensor. The battery current sensor monitors the battery current. It directly inputs to the BCM. It creates a 5-volt pulse width modulation (PWM) signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-95 percent. Between 0-5 percent and 95-100 percent are for diagnostic purposes.
  
  Engine Control Module (ECM)
  When the engine is running, the generator signal is sent to the generator from the ECM, turning on the regulator. The generator's voltage regulator controls current to the rotor, thereby controlling the output voltage. The rotor current is proportional to the electrical pulse width supplied by the regulator. When the engine is started, the regulator senses generator rotation by detecting AC voltage at the stator through an internal wire. Once the engine is running, the regulator varies the field current by controlling the pulse width. This regulates the generator output voltage for proper battery charging and electrical system operation. The generator field duty terminal is connected internally to the voltage regulator and externally to the ECM. When the voltage regulator detects a charging system problem, it grounds this circuit to signal the ECM that a problem exists. The ECM monitors the generator field duty cycle signal circuit, and receives control decisions based on information from the BCM.
  
  DTC B1516 08 : Battery Current Sensor Signal Invalid
  
  DTC B1516 66 : Battery Current Sensor Wrong Mounting Position
  
  Circuit/System Description
  The battery current sensor is a 3-wire hall effect current sensor. The battery current sensor monitors the battery current. It directly inputs to the body control module (BCM). It creates a 5-volt pulse width modulation (PWM) signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-95 percent. Between 0-5 percent and 95-100 percent are for diagnostic purposes.
  
  DTC B1517 Battery Voltage
  
  The body control module (BCM) has designated circuits for monitoring vehicle system voltage. The BCM monitors the system voltage to ensure that the voltage stays within the proper range. Damage to components, and incorrect data may occur when the voltage is out of range. The BCM monitors the system voltage over an extended length of time. If the BCM detects the system voltage is outside an expected range for the calibrated length of time, or the BCM battery sense circuits differ by 2 volts DTC B1517 will set. Other modules also monitor system voltage the system voltage message is sent to the other modules and will default to 12.9 volts.
  

15 volts is a bit high but I would check that against another tester. Is your battery boiling dry? In any case clean up the battery terminals and cable ends to make sure you have a good connection.

Hello Kevin, I think you should check and clean the battery cable connections at the battery. Also make sure they are tight.

Your probably going to need to take to a dealer for this , I don't how much you know about modern automotive charging systems . Plus it would help to have a professional scan tool ! The charging system on you vehicle is computer controlled ! The engine control module (ECM) controls the generator through the generator L-terminal control circuit. The signal is a 5-volt pulse width modulation (PWM) signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-95 percent. Between 0-5 percent and 95-100 percent are for diagnostic purposes. The following table shows the commanded duty cycle and output voltage of the generator:
The BATTERY SAVER ACTIVE message will display on the driver information center (DIC) when the vehicle enters a load shed 2 event. Refer to for load shed 2 setting criteria.
The electrical power management (EPM) system is designed to monitor and control the charging system and send diagnostic messages to alert the driver of possible problems with the battery and generator. This EPM system primarily utilizes existing on-board computer capability to maximize the effectiveness of the generator, to manage the load, improve battery state-of-charge (SOC) and life, and minimize the system's impact on fuel economy. The EPM system performs 3 functions:
It monitors the battery voltage and estimates the battery condition.

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It takes corrective actions by adjusting the regulated voltage.

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It performs diagnostics and driver notification
Load Shed 2 Start
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Less Than 10.9 V
Battery has a net loss greater than 12 AH
Rear defrost, heated mirrors, heated seats cycled OFF for 50% of their cycle. The BATTERY SAVER ACTIVE message will be displayed on the DIC.
You have a charging problem or battery problem !

turn the ignition switch to on do not start engine,withing 10 seconds depress the accelerator 3 times and turn key off,this resets the light to 100%,sometimes you have to do it a couple of times.

How I would solve this problem:

Check water level in battery if maintenance battery
Make sure both battery terminals are clean - use a battery terminal cleaner tool or wire brush.
Use a battery charger to see if battery is charged to 100%
If your battery is 100% percent I would put a voltmeter on your battery to see if your alternator is functioning properly. Depending on how many miles you have on your Jetta these Bosch brushes in the wear out. Replace the alternator if the output on the voltmeter is less than 14 volts.

If you are 100 percent sure that your battery is good then it is your starter going bad. I would take both the battery and starter to Auto Zone and they will test them both for you for free and let you know exactly which one needs to be replaced. Good luck and thanks for using FixYa!

Remove battery heads and replace after 5 minutes.

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