What it means
Battery Monitor Module 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 current, voltage, and temperature so the vehicle can manage charging and related features. This code sets when the module's overall reported performance does not match expected behavior, even though it may still communicate electrically.
Common causes
Most likely first.
- Module reads with drift
- Module software outdated, reflash may resolve
- Supply voltage outside specification
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 scan battery-monitor readings and related charging-system codes before clearing anything.
- Check battery state and charging-system operation, comparing measured voltage and module data with the manufacturer's specification.
- Inspect the battery monitor module, its supply and ground connections, and related connectors for corrosion, looseness, or damage.
- Check that the module's current, voltage, and temperature readings are plausible for the battery's actual condition and surroundings.
- If supplies and connections are sound, check for applicable module software updates and follow the manufacturer's diagnostic procedure before replacing the module.
Common fixes
- Clean and secure the module's power, ground, and connector connections.
- Correct a battery or charging-system condition that is driving module readings outside the manufacturer's specification.
- Update or reprogram the battery monitor module if an applicable manufacturer update addresses the fault.
- Replace the battery monitor module if its readings remain inaccurate after supply and software checks.
Can I keep driving?
Short trips may be possible if the battery and charging warnings are absent, but charging behavior or start-stop operation may be limited. If a charging warning appears or the vehicle struggles to start, avoid unnecessary driving and have the charging system checked promptly.
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.