System Voltage Out of Self-Test Range
Findings, check these first
- Weak battery during the self-test
- Charger connected skewing test voltage
- Failing alternator
- Corroded battery cables
- Excessive loads left on during the test
Standard procedure
- Charge the battery and switch off all loads
- Disconnect chargers before testing
- Verify charging voltage
- Clean cable ends
- Re-run the self-test with stable voltage
Code lookup
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Sources and review
Review: checked against the recorded source material.
- OBDII.pro: P1397 Ford definition
live reference page (obdii.pro)
Supports: Ford-family meaning for P1397: System Voltage Out Of Self Test Range
Fetched directly. obdii.pro is a publisher independent of the engine-codes family.
- P1397 FORD Code: Meaning, Causes, and Symptoms | OBD2 Codes
live reference page (obd2-codes.co)
Supports: Ford meaning for P1397: System Voltage Out Of Self Test Range
Fetched directly. obd2-codes.co phrasing matches the engine-codes family, so it counts as one publisher.
Last updated 2026-09-06.
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