What it means
The control module detected a fault related to the monitored voltage of hybrid/EV battery D.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The battery control system monitors the voltage assigned to hybrid/EV battery D, a specific monitored section of the high-voltage pack. This code flags a fault in that reading, but its title does not specify whether voltage is too high or too low; a cell-group imbalance, sense-circuit fault, or resistive ground can affect the measurement.
Common causes
Most likely first.
- Cell imbalance in this group
- Sense circuit fault
- Ground point with elevated resistance
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
How to diagnose it
- Record freeze-frame data and scan all battery-related codes, then compare battery D's reported voltage with neighboring sections to determine whether it is offset or unstable.
- With the vehicle powered down, visually inspect accessible battery D sense wiring, connectors, and low-voltage ground points for looseness, corrosion, or damage; do not open the high-voltage pack.
- Monitor battery D voltage and related battery data with a scan tool through the conditions captured in the freeze frame to see whether the fault follows charging, load, or temperature.
- Check the battery D sense circuit and its ground for poor contact, elevated resistance, or an open using the manufacturer's test procedure.
- If the wiring, ground, and sense circuit are sound, have a qualified hybrid technician assess battery D and neighboring sections for cell imbalance.
Common fixes
- Clean and secure an accessible low-voltage ground or connector with poor contact, following the manufacturer's procedure.
- Repair damaged or loose battery D sense-circuit wiring or connector pins.
- Repair a confirmed sense-circuit fault.
- Service or replace affected battery modules if testing confirms cell imbalance.
Can I keep driving?
If the vehicle remains in ready mode and has normal power, limit driving to a short trip for diagnosis; stop if power drops, a warning escalates, or it will not remain in ready mode. Reduced power or charging restrictions can worsen, and high-voltage components should be left untouched.
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.