Symptoms
- Hybrid system icon or triangle warning lit
- Possible loss of electric-only driving mode
- Car may feel like it's running only on the gas engine
Likely causes
- CommonHybrid battery cell imbalance or degradationSimilar to a regular battery, hybrid battery packs lose capacity and balance over years of use.
- CommonFaulty sensor in the hybrid drive systemSensors monitor battery temperature, voltage, and motor function.
- PossibleInverter or converter faultThese components manage power between the battery and electric motor.
- Less commonSoftware glitch requiring a system resetSometimes clears after turning the car off and back on.
What to do
- Note whether the car still drives, even if only on the gas engine.
- Turn the car off, wait a minute, and restart to see if the warning clears.
- Avoid pushing the car hard (highway merging, towing) until it's checked.
- Have the code read at a dealer or hybrid-specialized shop.
- Get the flagged sensor, battery module, or inverter repaired based on the diagnosis.
- Ask about the hybrid battery's overall health and remaining warranty if the pack is implicated.
When to call a pro
See a dealer or hybrid specialist, since these systems need specific training and tools most general shops don't have.
Safety
Use caution
Do not attempt to open or service the hybrid battery pack yourself; it carries high voltage that can be dangerous.