System Voltage Low
The P0562 code indicates that the Powertrain Control Module (PCM) has detected the vehicle's electrical system voltage has fallen below a specified threshold, typically under 10.0 to 12.0 volts, for a set period of time. This means the charging system is not providing adequate voltage to keep the battery charged and the vehicle's electronics functioning properly.
Low system voltage can cause the vehicle to stall while driving or fail to start, potentially leaving you stranded. It requires immediate attention to prevent complete electrical failure and loss of power steering or braking assists.
Common symptoms
- Illuminated Check Engine Light and Battery/Charging warning light
- Engine stalling, misfiring, or hesitation while driving
- Dimming headlights and interior lights
- Engine cranks slowly or completely fails to start
- Erratic behavior of dashboard gauges and electronic accessories
Likely causes
- Failing or defective alternator
- Weak, old, or defective 12-volt battery
- Loose, corroded, or damaged battery cables and terminals
- Damaged or slipping alternator drive belt (serpentine belt)
- Poor ground connection between the engine, body, and battery
- Faulty voltage regulator (if separate from the alternator)
What to check before replacing parts
Measure battery voltage with the engine off using a digital multimeter.
Look for: A healthy battery should read around 12.4 to 12.6 volts. A reading significantly lower indicates a discharged or failing battery.
Inspect the battery terminals and cables for corrosion or looseness.
Look for: Look for white or blue powdery buildup on the terminals or loose clamps that can be moved by hand, which restrict current flow.
Check the alternator drive belt (serpentine belt) condition and tension.
Look for: Look for cracks, fraying, glazing, or a loose belt that could slip and prevent the alternator from spinning at the correct speed.
Measure system voltage at the battery with the engine running.
Look for: The multimeter should read between 13.5 and 14.5 volts. If it remains near or below 12 volts, the alternator is not charging the system.
Perform a voltage drop test on the alternator power and ground circuits.
Look for: A voltage drop greater than 0.2 volts on either the positive cable to the battery or the alternator case ground indicates high resistance in the wiring.
This page explains the generic P0562 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
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