GarageGuideCharging system (system voltage low)
P0562 Code: System Voltage Low
P0562 stands for "System Voltage Low." The engine computer constantly monitors the car's electrical voltage. With the engine running, a healthy charging system usually holds roughly 13.5 to 14.7 volts. P0562 means the computer saw voltage drop below its expected range for long enough to set a code.
This code is about the car's whole electrical supply, not a single sensor. The usual suspects are the battery, the alternator that charges it, the belt that drives the alternator, and the cables and grounds that connect them. These are easy and often free to test.
P0562 may not stop the car right away, but low voltage can lead to a dead battery, stalling, or a no-start. If the alternator has failed, the car will run only until the battery is drained.
If the battery warning light is on, you may only have a limited amount of driving before the battery runs down. Turn off nonessential electrical loads like the radio and heated seats, and head straight to a parts store or shop. Avoid long trips or driving at night with dimming lights.
Symptoms you might notice
- Battery or charging warning light on
- Dim or flickering headlights and dashboard lights
- Slow cranking or a no-start
- Electrical glitches like a resetting radio or erratic gauges
- Engine stalling or running poorly at idle
- Squealing noise from a slipping drive belt
Common causes
Failing alternator
If the alternator is not charging enough, the system runs on battery power and voltage drops. This is one of the most common causes.
Weak or failing battery
A battery that cannot hold a charge pulls voltage down, especially at start-up and idle.
Loose or corroded battery terminals
Corrosion or a loose clamp adds resistance, so the computer sees low voltage even with good parts.
Bad ground connection
A corroded or loose engine or body ground strap causes low voltage readings and strange electrical behavior.
Slipping or worn drive belt
If the serpentine belt slips, the alternator cannot spin fast enough to charge properly.
Damaged alternator wiring or fuse link
A blown charging fuse or damaged cable between the alternator and battery stops the charge from reaching the battery.
Before you buy parts
P0562 points to the charging system as a whole, not a specific part. Test before buying. Clean the battery terminals first, then check voltage with the engine off and running, or get a free battery and alternator test at an auto parts store. That tells you whether you need a battery, an alternator, or just clean connections.
What to check
- Check the battery terminals for white or green corrosion and make sure both clamps are tight.
- Measure battery voltage with the engine off using a multimeter. Around 12.6 volts is fully charged; about 12.2 volts or less means the battery is low or weak.
- Start the engine and measure again. Roughly 13.5 to 14.7 volts means the alternator is charging; a reading that stays near battery voltage or drops points to the alternator or its wiring.
- Look at the drive belt for cracks, glazing, or looseness, and listen for squealing.
- Many auto parts stores test the battery, alternator, and starter for free, often right in the parking lot.
Possible repairs
Clean and tighten the battery terminals
Cleaning corrosion and tightening loose clamps is free or cheap and fixes many low-voltage problems.
Replace the battery
If the battery fails a load test, a new battery is usually a simple DIY replacement.
Replace the alternator
If the alternator fails testing, replacing it is a moderate job. On many cars it is DIY-friendly with basic tools.
Replace the drive belt or tensioner
A worn belt or weak tensioner that causes slipping is an inexpensive fix.
Repair grounds or charging wiring
Cleaning or replacing a bad ground strap, or replacing a blown charging fuse, restores proper voltage.
Parts and tools that may help
Enter your year, make and model on the store's site to see parts that fit your car.
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Frequently asked questions
What causes P0562?
Most often a failing alternator, a weak battery, or corroded or loose battery connections. A slipping drive belt or bad ground can also cause it.
Can I drive with P0562?
Only short trips. If the alternator is not charging, the car will run until the battery is drained and then stall. Head to a shop or parts store and turn off unneeded electrical loads.
Is P0562 the battery or the alternator?
It can be either. Measure voltage with the engine off and running, or get a free test at an auto parts store, to find out which.
What voltage should my car have?
Roughly 12.6 volts with the engine off and a full battery, and about 13.5 to 14.7 volts with the engine running.
Can corroded battery terminals cause P0562?
Yes. Corrosion adds resistance and can make the computer see low voltage. Cleaning and tightening the terminals is the first step.