What it means
The ECM detects a range/performance fault on the battery charger b current sensor circuit. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Battery charger B's current sensor reports how much current is flowing through that charger path so the control module can manage charging. This code sets when the sensor's reading is outside the expected range or does not track charging behavior plausibly, making it unreliable for control.
Common causes
Most likely first.
- Sensor characteristic drifted
- Sensor mounting displaced
- Sensor element aged beyond calibration window
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
How to diagnose it
- Use a scan tool to record freeze-frame data and compare charger B current with charging status and other available charging data to see when the reading becomes implausible.
- With the vehicle powered down according to the manufacturer's safety procedure, inspect charger B's current sensor mounting and connector for displacement, damage, corrosion, or poor seating.
- Check the sensor and its wiring for damage or looseness that could affect the reading, and repair any visible connection problem.
- Compare the current sensor signal with the manufacturer's specification during the specified charging test to identify drift or an unstable reading.
- If the wiring and mounting check out, test the sensor's response through its operating range and replace it if it has aged or drifted beyond specification.
Common fixes
- Reseat and secure the charger B current sensor if it has shifted.
- Clean or repair a poor sensor connector contact.
- Repair damaged wiring in the charger B current sensor circuit.
- Replace the out-of-calibration charger B current sensor.
Can I keep driving?
Charging may fail to start, pause, or run more slowly than expected, so avoid relying on the vehicle to recharge normally until the fault is diagnosed. If the charge status indicator warns of a fault, arrange another way to charge before depending on the vehicle for a trip.
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.