P0563 means the powertrain control module (PCM) has seen charging-system voltage above its calibrated high limit for longer than a set period. It usually points to an overcharging condition, or to a wiring/sensing issue that makes the PCM read voltage as higher than it really is.
An internally failed regulator can command the alternator to keep output too high, pushing system voltage above the PCM threshold.
A shorted, sulfated, or severely aged battery can cause the charging system to overcompensate and raise system voltage.
Corroded, loose, or high-resistance connections in the B+ cable, alternator output path, or grounds can make the PCM sense an incorrectly high voltage.
Non-factory alternators, high-output aftermarket units, or improper wiring modifications can produce voltage above the PCM's expected range.
Rarely, the PCM's internal A/D converter or voltage-sense input can fail and report a falsely high value after all actual charging-system tests are normal.
No. Sustained overcharging can overheat and ruin the battery and damage sensitive electronics, so the cause should be diagnosed promptly.
Often yes if the alternator's regulator is overcharging, but a failing battery or poor wiring can also produce the same code, so testing should be done before replacing parts.
Yes. A shorted or sulfated cell can make the charging system work harder and raise system voltage enough to set the code.
No. PCM failure is uncommon for P0563; most cases are caused by the alternator, battery, or charging-circuit wiring. The PCM should be suspected only after actual voltage and wiring have been verified as normal.