ACC Sensor Blocked
2016-2016 Cadillac ATS 2.5L I4
The 2016 Cadillac ATS is equipped with a 2.5L inline-4 engine. Below you'll find detailed c0405 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.
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 2016-2016 Cadillac ATS?
C0405 stands for "ACC Sensor Blocked". The adaptive cruise control sensor reports its view is obstructed.
What are the symptoms of C0405 on a Cadillac ATS?
Common symptoms of C0405 include: ACC temporarily unavailable message, Sensor blocked warning on dash, ACC disengages in bad weather.
What causes C0405 on a 2016-2016 Cadillac ATS?
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.
Last updated: March 2026