EZCarFix DIY Auto Repair

Diagnostic Trouble Code

P0562 — System Voltage Low

What it means, how urgent it is, the most likely causes, and the exact order to diagnose it — then pick your vehicle below for model-specific repair guides and parts.

Find P0562 for your vehicle

Pick your make and model for model-specific repair guides, parts, and costs.

What P0562 means

P0562 means the engine computer has detected that system voltage is too low — the electrical system is running below its minimum threshold. your vehicle's electronics expect roughly 12.6 volts with the engine off and 13.7–14.7 volts with it running. The PCM watches system voltage continuously; when it stays below about 10–11 volts for a set time, P0562 sets and the check engine light comes on. Low voltage is usually a symptom, not the disease: either the battery cannot hold charge, or the alternator cannot make enough of it. Electrical gremlins that seem random — flickering lights, weak cranking, modules acting strangely — often trace back to exactly this.

Applies to 404 vehicles across 41 makes.

⚠️ How urgent is it?

Driveable, but with a deadline. If the alternator is the problem, the car is running on battery alone and will stall when the battery depletes — potentially leaving you stranded with no warning beyond dimming lights. Check it the same day if possible: most auto parts stores test batteries and alternators free. If voltage is dropping while driving (lights dimming, gauges flickering), head straight somewhere safe — you are on borrowed time.

Most likely causes

  1. A weak or failing battery that can no longer hold a charge — the most common cause, especially on batteries over 3–4 years old.
  2. A failing alternator not producing enough output to maintain system voltage.
  3. Corroded, loose, or damaged battery terminals and cables creating resistance.
  4. A parasitic drain slowly depleting the battery overnight.
  5. Bad engine or chassis ground straps.
  6. A faulty voltage regulator (internal to most modern alternators).

How to diagnose P0562

  1. Measure battery voltage with the engine off. A healthy battery reads about 12.6V; 12.0V or less means it is significantly discharged.
  2. Measure voltage with the engine running. You should see roughly 13.7–14.7V. Below 13.5V with loads on points to the alternator.
  3. Load-test the battery. Voltage alone can lie — a proper load test reveals a battery that collapses under demand.
  4. Inspect and clean the battery terminals and cable ends. Corrosion here causes voltage drop that mimics a bad battery or alternator.
  5. Check alternator output under load: headlights, blower, and defroster on, engine at 2,000 RPM — voltage should hold in the normal charging range.
  6. If the battery and alternator test good but voltage keeps dropping overnight, test for parasitic drain with an ammeter (normal draw is typically under 50 milliamps).

General diagnostic information, not a factory service procedure. If you're unsure, have a qualified technician confirm the diagnosis before buying parts.