OBD CodesWhat it means
The computers need a steady supply of about 12 to 14.5 volts. These codes mean the voltage seen by the engine computer was too low, too high or unsteady for some time. Low voltage also triggers many other false codes, so fix this first.
Codes in this group
| Code | Meaning |
|---|---|
| P0560 | System voltage fault |
| P0561 | System voltage unstable |
| P0562 | System voltage too low |
| P0563 | System voltage too high |
Bank 1 is the side of the engine that has cylinder 1. Sensor 1 is before the catalytic converter and sensor 2 is after it. More terms explained.
What you may notice
- Slow cranking or clicking when starting
- Battery warning light
- Dim lights, or lights that brighten with engine speed
- Several unrelated warning lights at once
Common causes
Most likely first:
- A worn-out battery
- A failing alternator or its regulator
- Loose or corroded battery terminals or earth straps
- A slipping or broken drive belt
- A faulty voltage regulator overcharging (too high)
What to check first
- Check that the battery terminals are tight and free of white or green crust
- Have the battery and alternator tested: many workshops and battery shops do this quickly
- Clear the other codes after the supply is fixed and see which ones return
Have a mechanic confirm. A fault code tells you which system reported a problem, not which part has failed. The same code can have several causes, and they differ between car models. Use this page to understand the code, then have a qualified mechanic test the car before any part is replaced.
After the repair
Once the cause is fixed, the code can be cleared with a scan tool, or the warning light goes out by itself after several trips without the fault. Clearing a code without fixing the cause only hides it for a while. More about clearing codes.
Related codes
Engine overheating or overspeed (P0217), Fuel level sensor (P0460), Radiator cooling fan circuit (P0480), Vehicle speed sensor (P0500), Idle speed control (P0505), Brake pedal switch (P0504), Engine oil pressure sensor (P0520), Air conditioning pressure sensor (P0530). All codes.
Written in November 2026. These are generic OBD-II codes, the same on all makes. Causes and repair steps differ between models.