Toyota, Lexus Warning Message
“Check Hybrid System”
A fault has been detected in the hybrid powertrain system. This may involve the hybrid battery, inverter, MG1/MG2 motor-generators, or the hybrid control ECU. The vehicle may lose electric assist or enter a reduced power mode.
critical severity
Common Causes
- Hybrid battery cell degradation
- Inverter coolant pump failure
- Hybrid battery cooling fan blockage
- High-voltage cable insulation fault
- Hybrid control ECU communication error
Immediate Action
The vehicle may still be drivable in a reduced mode. Do not ignore this warning — hybrid system faults can escalate. Schedule service immediately.
Typical Repair Cost
$1,000–$6,000+