Battery Voltage Out of Range - Body Control Module

The body control module (BCM) is noticing that the battery voltage is either too low (below 9 volts) or too high (above 16 volts) when it should be between 12.5 to 14.5 volts when the engine is running. This could be caused by a bad alternator, weak battery, or bad wiring.

The BCM monitors battery voltage continuously. It flags the code when voltage readings don't fall within expected ranges during startup or operation.

Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.

1. 11. Check the battery voltage with a multimeter. Confirm if it's below 9V or above 16V. If it's normal (12.5 - 14.5V), go to step 7.
2. 22. Inspect battery terminals for corrosion and tightness. Clean and tighten if necessary. Recheck voltage. If still out of range, go to step 3.
3. 33. Check the alternator output while the engine is running. It should be around 14V. If low or high, test or replace the alternator.
4. 44. Inspect the wiring to and from the battery and BCM for damage or loose connections. Repair as needed. Retest voltage.
5. 55. If voltage is still not within range, consider testing the BCM for faults. Use a scan tool for advanced diagnostics.
6. 66. If the battery is old (over 4-5 years), consider replacing it and see if the problem resolves.
7. 77. If all checks are normal and the code returns, it may indicate a faulty BCM or software issue.

• Weak or damaged battery
• Faulty alternator
• Corroded or loose battery connections
• Wiring issues between the battery and BCM
• BCM software needing an update

$$ (200-500)