P0562 Code: System Voltage Low
Quick Answer
The ECU detected that the electrical system voltage is lower than it should be — typically from a weak battery or failing alternator.
At a Glance
What this code means
The ECU monitors battery and system voltage to ensure all electronic systems have adequate power. P0562 means the voltage has dropped below approximately 10–11V for a sustained period. This can cause a wide range of seemingly unrelated symptoms because many sensors and actuators operate incorrectly at low voltage.
Common causes
- Weak or failing battery (most common)
- Failing alternator not charging adequately
- Excessive current draw from an aftermarket accessory
- Loose, corroded, or damaged battery cables or ground straps
- Failing voltage regulator
Symptoms you might notice
- Dim headlights or flickering interior lights
- Battery warning light on the dashboard
- Check engine light on
- Multiple other seemingly unrelated codes appearing simultaneously
- Slow engine cranking
- Electrical accessories behaving erratically
Can you still drive?
With caution. A failing battery or alternator can leave you stranded. Have the charging system tested immediately.
How serious is this code?
High. Low system voltage can strand you and cause cascading electrical issues.
Before you replace parts
Parts replacement is often not the first step. Before buying anything, it's worth checking these basics:
- Have the battery load-tested (not just voltage-tested) — a battery can show 12.4V at rest but fail under load; voltage alone is not a reliable test
- Check all battery cable connections and ground straps — a loose ground can cause low voltage readings without any actual charging system failure
How to troubleshoot it
- Test battery voltage with a multimeter — should read 12.4–12.6V at rest with engine off
- Start the engine and test voltage at the battery — should be 13.5–14.8V (charging system working)
- Inspect battery terminals and cable connections for corrosion or looseness
- Inspect the main ground strap from the battery to the chassis and engine block
- Have the battery and alternator load-tested at an auto parts store (often free)
Tools that may help
These are the types of tools commonly used when diagnosing this code. Having the right tool can save time and help confirm a diagnosis before spending money on parts.
- Multimeter
- Battery load tester
Estimated repair cost range
Battery replacement: $100–$300. Alternator replacement: $250–$700. Battery cable repair: $100–$300.
Costs vary significantly by vehicle, location, and whether you use OEM or aftermarket parts. These are general ranges for reference only.
When to call a mechanic
If you've completed the basic troubleshooting steps and the code keeps returning, or if you don't have access to the proper diagnostic tools, it's worth consulting a professional. A qualified technician can perform a full diagnosis and confirm the root cause before any parts are purchased. When in doubt, get a professional opinion — it can save you from an expensive misdiagnosis.
Real-world note
Many auto parts stores will test your battery and alternator for free. This is the first step — before any other diagnosis. A weak battery that passes a simple voltage test but fails under load is a very common issue on vehicles 4+ years old.
Related Codes
Informational purposes only. This guide is for educational reference and is not a substitute for diagnosis by a qualified technician. Repair costs, causes, and symptoms may vary by vehicle make, model, year, and condition. Always consult a licensed mechanic before performing major repairs.