P0562 System Voltage Low
Charging system voltage is below what the computer expects — most often a failing alternator, a bad belt, or corroded battery connections.
Electrical & idle
The ECU monitors system voltage and expects roughly 13.5 to 14.5 volts with the engine running. P0562 means it saw meaningfully less. Every module on the vehicle depends on stable voltage, so low system voltage can produce a scatter of unrelated-looking codes and strange behaviour across systems — which is why chasing those other codes first is a common waste of time.
Diagnose P0562 on your specific vehicle Add your year, make and model for ranked causes, repair videos and the exact parts you needCan I keep driving?
Driveable
Only as far as you need to get it fixed, and preferably with the headlights and heater off. When the battery runs down the engine stops, and power steering and brake assist go with it.
How serious
High. This is a stranding fault. Once the battery is doing the work the alternator should, you have a limited and shrinking amount of driving left.
Symptoms you'll notice
- Battery or charging warning light
- Dim or flickering headlights, especially at idle
- Slow cranking or failure to start
- Multiple unrelated warning lights and odd electrical behaviour
- Stalling
What causes P0562
Ordered by what to check first — how likely each cause is, weighed against what it costs to rule out. Working down the list in order is what stops you replacing an expensive part to fix a cheap problem.
Failing alternator
The most common cause. Worn brushes, failed diodes, or a bad internal regulator. A load test at an auto parts store settles it quickly and usually for free.
Corroded or loose battery terminals
Check this first because it costs nothing. Corrosion adds resistance that drops voltage under load, and cleaning terminals has fixed more charging complaints than any part swap.
Worn or slipping serpentine belt
A glazed belt or a failed tensioner means the alternator spins slower than it should, particularly at idle and with a heavy electrical load.
Failing battery
A battery with a shorted cell loads the alternator continuously and drags system voltage down even with a healthy alternator.
Bad ground connections
Corroded engine-to-body or battery-to-chassis ground straps cause voltage drop that mimics a charging failure.
Damaged charging cable
The heavy cable from alternator to battery can corrode internally under intact-looking insulation.
How to diagnose it
- Measure battery voltage with the engine off — around 12.6 volts is a healthy resting battery.
- Measure again with the engine running; it should sit between roughly 13.5 and 14.5 volts. Below that confirms a charging fault.
- Clean and tighten the battery terminals and check the ground straps before buying anything.
- Inspect the serpentine belt for glazing, cracking and correct tension.
- Have the alternator and battery load-tested — most parts stores do this free.
- Perform a voltage drop test along the main charging cable and grounds to find hidden resistance.
Parts you might need
Tools for the job
- Multimeter
- Battery load tester
- Wire brush
- Serpentine belt tool
Related trouble codes
Get the parts list for your vehicle Ranked causes, tutorials and live part prices for your exact year, make and modelFitment matters. Causes and parts above are the common cases for P0562 across vehicles. The specific part numbers, procedures and torque specs vary by year, make, model and engine — always confirm against service data for your vehicle before buying parts or starting work.