P0562 System Voltage Low: An Evidence-First Diagnostic Checklist

P0562 means the control module has seen system voltage below its expected operating range. The code does not, by itself, prove that the battery or alternator has failed. Loose connections, excessive cable resistance, poor grounds, high cranking load, and intermittent charging faults can create the same symptom.

Preserve evidence before clearing the code

1. Save stored, pending, and history codes from every available module.
2. Record freeze-frame voltage, engine speed, load, and vehicle speed.
3. Measure rested battery voltage after surface charge has dissipated.
4. Capture minimum voltage during cranking; compare the meter reading with scan-data voltage.
5. With the engine running, test charging voltage at idle and under electrical load.
6. Perform loaded voltage-drop tests on the positive and ground paths. A continuity check alone can miss resistance that appears only under current.

If several modules report undervoltage or communication faults at the same timestamp, diagnose the shared power and ground supply before condemning an individual control module.

Confirm the repair

After correcting the electrical fault, clear codes only after the original evidence is saved. Repeat the same cranking and loaded-charging tests, then run a full vehicle scan and confirm that system voltage remains stable.

For compatible scan tools and official United States product support, visit iCarsoft-US Official Authorized Store.

Technical educational resource published September 8, 2026. Vehicle-specific procedures and voltage limits should be confirmed with the applicable service information.