What it means
Battery Monitor Module Voltage Monitoring Performance: the component is electrically intact but its response does not match the command. The module reports battery current, voltage and temperature for charge management.
At a glance
- Usually lights the check-engine light
How it works
The battery monitor module measures battery voltage as part of its charge-management calculations. This code sets when its voltage-monitoring response does not behave as expected, potentially causing the vehicle to misjudge the battery's charge state.
Common causes
Most likely first.
- Battery voltage sensor or measurement fault
- Loose, corroded, or damaged sensor connections
- Damaged wiring
- Battery-monitor module fault
Symptoms
- Battery or charging warning light may appear
- Start-stop system may be unavailable
- Charging behavior may change
How to diagnose it
- Record freeze-frame data and compare the module's battery-voltage reading with a suitable meter reading taken at the battery under the same conditions.
- Inspect the battery terminals and voltage-measurement connections for looseness, corrosion, or damage.
- Check the battery monitor module's voltage-sensing wiring and connectors for chafing, pin damage, or poor contact.
- Check battery and charging-system voltage against the manufacturer's specification and note any related charging faults.
- If the measured voltage and connections are sound but the module reading is inaccurate, follow the manufacturer's test procedure for the module.
Common fixes
- Clean and tighten the battery terminals and voltage-sensing connections.
- Repair damaged wiring or connector terminals in the voltage-monitoring circuit.
- Correct a battery or charging-system fault that is causing voltage readings outside the manufacturer's specification.
- Replace the battery monitor module if its voltage reading fails the specified checks.
Can I keep driving?
Driving may be possible if the vehicle starts and no charging warning is present, but inaccurate voltage monitoring can affect charging decisions. If the charging warning appears or electrical systems begin to falter, stop when safe and have the system checked.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.