Toyota Corolla
U0421
The U0421 code in a 2019-2024 Toyota Corolla E210 indicates an invalid data received from the vehicle’s battery energy control module (BECM). This can lead to various electrical and performance issues.
1 SolutionU-CodeNetwork
U
Error Code Type
Network
Components
1 affected
Electrical
Symptoms
5 common
- •Check engine light illuminated
- •Erratic or non-functional electrical accessories
- •Poor fuel economy
- +2 more
Most Affected Generations
1 generation
E210
1
Top Affected Components
1 component
Electrical
1
Severity Levels
1 level
medium
1
Quick Facts
1
Total Solutions
1
Affected Components
5
Common Symptoms
1
Generations
All Solutions
Showing 1 of 1 solution for error code U0421 across all generations.