System Voltage Malfunction
What does P0560 mean?
The P0560 code means the vehicle's onboard diagnostic system has detected: System Voltage Malfunction. This is a moderate severity code.
Common Symptoms
- Battery warning light on dash
- Dim headlights or interior lights
- Electrical accessories malfunctioning
- Engine running rough or stalling
- Check engine light on
Probable Causes (Ranked by Likelihood)
- Failing alternator not maintaining proper voltage Very High
- Weak or failing battery High
- Corroded or loose battery cables/terminals High
- Faulty voltage regulator (internal or external) Moderate
- Damaged charging system wiring or main fuse Low
Step-by-Step Diagnostic Procedure
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Measure battery voltage with engine off -- should be 12.4-12.7V for a fully charged battery
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Measure voltage with engine running at idle -- should be 13.5-14.5V (alternator charging)
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Load test the battery -- voltage should not drop below 9.6V during a 15-second load test
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Inspect battery terminals and cable connections for corrosion -- clean with baking soda and wire brush
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Test alternator output with a multimeter -- check for AC ripple voltage (should be less than 0.5V AC)
Frequently Asked Questions
Can I drive with code P0560?
You can drive short distances, but be aware that if the alternator is failing, the battery will eventually drain and the vehicle will stall. Avoid using high-draw accessories like AC, heated seats, and stereo to extend your driving range.
How do I know if it is the battery or the alternator?
Measure voltage with the engine running. If voltage is below 13.5V with the engine on, the alternator is likely failing. If the battery voltage is below 12.4V with the engine off and the alternator tests good, the battery needs replacement. Most auto parts stores will test both for free.
Can a bad battery cause this code?
Yes. A battery with a shorted cell or one that cannot hold a charge can cause system voltage to be abnormal, even if the alternator is working correctly. The PCM monitors system voltage and sets this code when it falls outside the expected 11.5-16V range.