C0405
ACC Sensor Blocked
2014-2021 Mazda Mazda6 2.5L I4
Low SeverityChassisGeneric (SAE)
Description
The adaptive cruise control sensor reports its view is obstructed.
Symptoms
- ACC temporarily unavailable message
- Sensor blocked warning on dash
- ACC disengages in bad weather
Common Causes
- Mud, snow, or ice covering sensor area
- Aftermarket grille or bumper cover blocking sensor
- Heavy rain or fog
- Damaged sensor cover or radome
Diagnostic Steps
- Clean radar sensor cover or camera lens
- Inspect bumper fascia sensor opening
- Check for aftermarket parts blocking sensor
- Verify no damage to sensor radome
- Test in clear weather to confirm resolution
Repair Notes
Clean sensor area thoroughly. Remove any aftermarket obstructions. Replace damaged radome.
Related Codes
Other Chassis Codes
- C0021LF Wheel Speed Sensor Range/Performance
- C0022RF Wheel Speed Sensor Range/Performance
- C0023LR Wheel Speed Sensor Range/Performance
- C0024RR Wheel Speed Sensor Range/Performance
- C0025LF Wheel Speed Sensor Circuit Intermittent
- C0026RF Wheel Speed Sensor Circuit Intermittent
- C0027LR Wheel Speed Sensor Circuit Intermittent
- C0028RR Wheel Speed Sensor Circuit Intermittent
- C0035Left Front Wheel Speed Sensor Circuit
- C0036Left Front Wheel Speed Signal Erratic
C0405 on Other Vehicles
Common Questions
What does code C0405 mean on a 2014-2021 Mazda Mazda6?
C0405 stands for "ACC Sensor Blocked". The adaptive cruise control sensor reports its view is obstructed.
What are the symptoms of C0405 on a Mazda Mazda6?
Common symptoms of C0405 include: ACC temporarily unavailable message, Sensor blocked warning on dash, ACC disengages in bad weather.
What causes C0405 on a 2014-2021 Mazda Mazda6?
Common causes of C0405 include: Mud, snow, or ice covering sensor area, Aftermarket grille or bumper cover blocking sensor, Heavy rain or fog, Damaged sensor cover or radome.