What it means
The supply voltage to battery charger B control module is low. Charger may not start or operate reliably.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Battery charger B needs a stable low-voltage supply to run its control electronics. The vehicle monitors that supply and sets P2E30 when it falls below the acceptable range, which can prevent charger B from starting or make charging unreliable.
Common causes
Most likely first.
- Module supply fuse blown
- Wiring fault
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
How to diagnose it
- Read freeze-frame data and charging-module live data to see when charger B supply voltage fell and whether the fault is present now.
- Check the relevant charger B supply fuse and its connections for a blown element, looseness, or heat damage.
- With the vehicle powered down as specified by the manufacturer, inspect charger B's low-voltage supply wiring and connectors for damage, corrosion, or loose pins.
- Measure voltage at the charger B supply and ground under the conditions specified by the manufacturer, then compare it with the manufacturer's specification.
- If the fuse, wiring, and supply readings are sound, follow the manufacturer's circuit checks to determine whether the fault is inside charger B or its control module.
Common fixes
- Repair a loose or corroded charger B supply connection.
- Repair damaged or open supply wiring.
- Replace a blown supply fuse after checking for the cause.
- Repair or replace the charger B control module if circuit tests confirm an internal fault.
Can I keep driving?
Charging may fail or stop, so do not rely on the vehicle having the range you expect; arrange another way to charge before a trip. If the vehicle reports a high-voltage system warning, follow its instructions and avoid handling charging components.
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.