P0562 – System Voltage Low

What does P0562 mean?

The computer has detected that system voltage is below the normal operating range. Modern vehicles need stable voltage for every electronic module, so low voltage can cause a cascade of unrelated-looking faults across the vehicle.

What causes P0562?

Listed from most to least common:

1. 1Failing alternator (most common)
2. 2Weak or failing battery
3. 3Corroded battery terminals or cables
4. 4Loose or worn serpentine belt
5. 5Bad ground connection
6. 6Failing voltage regulator
7. 7Excessive parasitic drain

Code breakdown

Common symptoms

• Check engine light on, often with other unrelated warning lights
• Dim or flickering headlights
• Battery warning light
• Slow cranking or no start
• Multiple modules reporting faults simultaneously
• Electrical accessories behaving erratically

How to diagnose

1. 1Measure battery voltage with the engine off — roughly 12.6V is healthy.
2. 2Measure voltage with the engine running. It should typically be around 13.5–14.5V; readings below this point to a charging fault.
3. 3Inspect battery terminals and cables for corrosion and looseness.
4. 4Check the serpentine belt tension and condition.
5. 5Perform a load test on the battery.
6. 6Test alternator output under electrical load with headlights and blower on.
7. 7Check ground strap connections between engine, body, and battery.

Low system voltage can leave you stranded and can cause erratic behavior in multiple systems. Treat it as urgent, especially if warning lights are appearing.

Common fixes and estimated costs

Costs are rough US estimates including parts and labor. Actual pricing varies significantly by vehicle, region, and shop rates.

Good to know

When multiple unrelated warning lights appear at once, check charging system voltage before chasing individual module codes. Low voltage produces false faults across many systems, and fixing the charging problem often clears all of them.

Related codes