C0431moderate severityChassis
Lane Keeping Assist Steering Intervention Fault
on 2019 Mazda Mazda3 2.5L I4 · FWD
What this code means
The lane keeping assist system cannot apply corrective steering through the EPS system.
Symptoms
- LKA disabled
- Lane keep warning light
- System available in warning mode only
Common causes
- EPS fault preventing LKA torque application
- Steering torque sensor error
- LKA module communication fault
- Steering angle sensor not calibrated
Diagnostic steps
- Check for EPS trouble codes
- Verify steering angle sensor calibration
- Test EPS torque application capability
- Check CAN communication between LKA and EPS modules
- Inspect steering system for mechanical issues
Repair notes
Resolve EPS faults first. LKA requires a fully functional EPS system to apply corrective steering.
Other Chassis codes on this vehicle
C0021
LF Wheel Speed Sensor Range/Performance
C0022
RF Wheel Speed Sensor Range/Performance
C0023
LR Wheel Speed Sensor Range/Performance
C0024
RR Wheel Speed Sensor Range/Performance
C0025
LF Wheel Speed Sensor Circuit Intermittent
C0026
RF Wheel Speed Sensor Circuit Intermittent
C0027
LR Wheel Speed Sensor Circuit Intermittent
C0028
RR Wheel Speed Sensor Circuit Intermittent
C0035
Left Front Wheel Speed Sensor Circuit
C0036
Left Front Wheel Speed Signal Erratic