The BMW Technician Training Document on BMW Battery System is a useful resource for getting started in the process of comprehending the BMW Battery System. Informational Document about the BMW Battery
Step 1 Instructions on how to use the self-check function of the BMW instrument cluster to determine the voltage of the car’s battery in a BMW E38, E39, or E46.
Put the car in park.
Turn on the headlights with the high beam setting for a period of 5 minutes. This gets rid of the surface charge so the testing may be done correctly.
Stop using the high beams of your headlights.
While you are doing so, turn the ignition key to the first position and continue pressing and holding the Check Control button that is located in the instrument cluster (the RIGHT button) (KLR).
First, you will see the words “Check Control OK,” and then a few seconds later, you will see the words “Test Nr.01.”
You may see the vehicle’s identification number by selecting Test Number 1 and then pressing the left button on the instrument cluster. Sum the first five digits (not 6)
Compute the sum of the digits. For example, if we plug in A123457, we get 2+3+4+5+7, which is 21.
You need to keep pressing the right button till you see the words “Test Nr. 19.”
Make sure you use the LEFT button to enter the entire amount that you estimated before into this menu option. When you are finished, hit the right button one again. Your instrument cluster will become unlocked as a result, and you will have full access to all of the test modes.
Select System Voltage using the button on the left after selecting Test Number 9.
To make your selection, use the Right button. Your vehicle’s battery voltage will be shown on the High Cluster until such time as you switch the vehicle off once again.
How can I determine whether the battery in my BMW is healthy?
A quick visual inspection of the battery may be done quickly and effectively to determine the state of charge of the battery. First start the vehicle, and then switch on the headlights. Check to determine whether the lights are completely illuminated or if they have a dimmer appearance. If they are dim, this indicates that the battery rather than the alternator is being drawn upon to power them.
What may be preventing my car’s battery from being charged?
Corrosion is one of the most frequent causes for the battery light to turn on and for the vehicle battery to cease charging after it has been fully charged. It makes no difference whether the rust is on the cable terminals or the battery cables; either way, it is an issue that has to be fixed. Alternator issues are another typical cause of the battery not being charged, particularly in older vehicles.
How can I determine whether or not the battery in my device needs to be recharged?
The engine of your automobile is difficult to start…
The electrics in your vehicle are seeing a decrease in power…
Your vehicle’s dashboard displays a battery warning light that has illuminated…
The start-stop feature in your automobile is no longer operational…
The age of your battery is more than five years.
How do you tell whether the battery in your BMW needs to be replaced?
Headlights becoming dimmer
a requirement for engine revving or jump starting much more often.
When you turn the key or press the button, it takes much longer for the engine to start.
Unusual shifts in the power level.
How can you determine whether there is an issue with the charging system?
Testing the voltage of the charging system is not difficult. Load the charging system by adding an electrical load such as the headlights, blower motor, or windshield wipers. Make sure the voltmeter is connected to the battery before beginning this process. The voltage at which the battery is charged should be within the range specified by the manufacturer, which is often between 13 and 15 volts.