System Voltage Low (P0562)
The P0562 code indicates that the powertrain control module (PCM) has detected a system voltage below the specified threshold, typically under 10 volts for an extended period. This can be caused by a failing alternator, weak battery, corroded battery terminals, or wiring issues. The PCM monitors voltage at the battery and alternator; when voltage drops, it triggers this code to alert the driver of a charging system problem.
1. Most Common Causes
- Faulty battery (sulfated, shorted cells, or worn out)
- Failed alternator (voltage regulator, rectifier, brushes, or rotor)
- Loose, worn, or broken alternator drive belt
- Loose, corroded, broken, or shorted wiring in the charging circuit (B+ or ground)
- Blown fuses or fusible links in the charging circuit
- Internal PCM failure (rare, but possible in the voltage monitoring circuit)
2. Symptoms You Will Notice
- Battery or check engine light illuminated
- Dimming headlights or interior lights
- Slow engine crank or no start
- Electrical accessories malfunctioning
3. Step-by-Step Diagnosis
Step 1: Check battery voltage with a multimeter (should be 12.6V+ engine off, 13.5-14.5V running).
Step 2: Inspect battery terminals for corrosion and clean if necessary.
Step 3: Test alternator output at the battery with engine running.
Step 4: Check for parasitic draw if battery drains overnight.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Low voltage can cause stalling, poor performance, and may leave you stranded. Have it diagnosed immediately.
How much does it cost to fix?▼
Typically $50-$150 for diagnosis and minor repairs like terminal cleaning; alternator replacement can cost $200-$600.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.