What does it mean?
B1317 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Battery Voltage High .
Symptoms
- Charging or battery warning lamp lit, often with several body modules storing codes together
- Lamps burn unusually bright and bulbs fail frequently
- Battery gets hot, smells acidic, or vents electrolyte
- Displays flicker or reset and electrical accessories behave erratically
- In severe cases the battery case swells
Likely causes
- Overcharging alternator with a failed internal or externally controlled voltage regulator
- Charging strategy commanding excessive output because of faulty battery management data
- Battery sensor at the negative terminal faulty, or its connector corroded, giving false state-of-charge information
- Poor battery ground causing regulation errors
- Jump starting from an unsuitable supply, or a charger left connected on a high setting
- Wrong battery type fitted without recoding, so the charging strategy is inappropriate
- Fault in the module's own voltage monitoring circuit
How to fix it
- Measure charging voltage right at the battery with the engine idling and at raised rpm, it must stay within specification
- Compare the measured value with the voltage reported by the scan tool
- Check the battery sensor at the negative terminal and read its data
- Voltage-drop test the battery grounds and the main charging cable
- Confirm the battery is the correct type and has been registered or coded if the vehicle requires it
- Replace the voltage regulator or the alternator when output remains above specification
- Recheck every module for stored voltage codes after the repair, clear them and retest on a road test