Speed, idle & inputs · Powertrain · generic (SAE-defined)
P0562: System Voltage Low
P0562 means the engine computer has detected that the vehicle's electrical system voltage is lower than it should be while the engine is running.
Standard title per SAE J2012 / ISO 15031-6 · Updated 2026-11-07 · By CarWhere Research
How P0562 sets
The powertrain control module (PCM) continuously monitors the voltage on its power supply. If the voltage stays below a minimum calibrated value for a set time with the engine running, it sets P0562. The voltage threshold and timing are manufacturer-specific.
Common causes of P0562
Roughly most likely first; the actual cause depends on the vehicle and needs testing to confirm.
- Failing alternator or voltage regulator
- Weak or failing battery
- Loose, corroded, or damaged battery terminals or cables
- Worn or slipping drive belt
- Poor ground connections
- Excessive electrical load from aftermarket accessories
P0562 symptoms
- Check engine light on
- Battery or charging warning light
- Dim or flickering lights
- Slow cranking or no start
- Engine stalling or erratic electrical behavior
How P0562 is diagnosed
- Check battery voltage with the engine off and running
- Inspect battery terminals, cables, and grounds for corrosion or looseness
- Inspect the drive belt for wear and tension
- Load test the battery
- Test alternator output under load
- Check voltage drop on power and ground circuits to the PCM
Typical fixes for P0562
- Replace the alternator or voltage regulator
- Replace the battery
- Clean or repair battery terminals and cables
- Replace the drive belt or tensioner
- Repair ground connections
Replace parts only after testing confirms the cause — a code names the circuit or condition that failed a check, not necessarily the faulty part. We don’t publish per-repair prices; for what households actually spend on upkeep, see car repair costs.
Manufacturer notes
Definitions can vary by manufacturer; check factory service information. Vehicles with smart charging systems may command lower voltage under certain conditions.
Related codes & warning lights
P0562 FAQ
What does code P0562 mean?
P0562 means the engine computer has detected that the vehicle's electrical system voltage is lower than it should be while the engine is running. The standard definition is "System Voltage Low."
Can I drive with a P0562 code?
Limit driving. Low system voltage often means the alternator is not charging, and the battery can run down until the engine stalls, sometimes without warning. Turn off unnecessary electrical loads and get the charging system tested as soon as possible.
Can a bad battery cause P0562?
Yes. A battery with a weak or shorted cell can drag system voltage down, though alternator problems are also common causes.
Why does my car have other strange electrical issues?
Low voltage affects many modules at once, which can lead to warning lights, erratic gauges, or communication codes.
Keep researching
More speed, idle & inputs codes
Sources
- SAE J2012 — Diagnostic Trouble Code Definitions (standard code titles)
- ISO 15031-6 — Road vehicles: communication between vehicle and external equipment for emissions-related diagnostics, Part 6: Diagnostic trouble code definitions
- U.S. EPA — Vehicle Emissions Inspection and Maintenance (I/M) programs
- U.S. EPA, 40 CFR 86.1806-17 — Federal onboard diagnostics requirements for light-duty vehicles
General information written by CarWhere Research, not a diagnosis of your vehicle. Manufacturers can add their own sub-definitions and test conditions; confirm with the factory service information for your year, make and model. Before paying for a repair, check NHTSA for open recalls and your warranty booklet: federal law requires an emissions warranty on major emission-control parts such as the catalytic converter and engine computer.