Fault code P0561 – a step-by-step guide to diagnosing and fixing it

Error code P0561 is displayed and the check engine light is on - what does this mean?

DTC P0561 is recognized by the OBD/EOBD system when the system voltage is unstable or outside the specified parameters. This fault code affects the vehicle's electrical system and can affect various control units. For some manufacturers, this code may also be referred to as "System Voltage Unstable" or "Charging System Performance".

What can cause this error code?

• Defective alternator
• Weak or defective battery
• Damaged cables in the charging system
• Loose or corroded battery terminals
• Defective voltage regulator
• Overloading of the electrical system
• Defective fuses or relays
• Poor earth connections
• Defective control unit

What symptoms occur in parallel with fault code P0561?

• Starting problems: The vehicle is difficult or impossible to start
• Fluctuating lighting: Headlights and interior lighting flicker or dim
• Electronic faults: Radio, navigation or other electrical components work irregularly
• Loss of engine power: Reduced power or rough idling
• Battery warning light: Additional warning indicators on the dashboard
• Charging system problems: Battery not charging properly

How to fix the problem of error code P0561?

• The elimination of error code P0561 requires a systematic check of the electrical system.
• Test battery and replace if necessary - voltage should be between 12.4-12.6V in idle state
• Check alternator and replace defective components - charging voltage should be 13.5-14.5V
• Clean and tighten all battery terminals and treat with terminal grease
• Check cable connections in the charging system for damage and corrosion and repair them
• Test voltage regulator and replace if defective
• Check and restore earth connections between the engine and bodywork
• Reduce electrical loads and remove unnecessary additional devices
• Check fuses and relays in the charging system and replace defective parts