Home >> Land Rover >> 2021 >> Range Rover SVAutobiography Dynamic Blk. >> Repair and Diagnosis >> Quick Lookups >> Common Specs & Procedures >> Diagnostic Trouble Code Index DTC: Head Up Display (HUD) -- Range Rover/L405 >> General Information >> Description And Operation >> Diagnostic Trouble Code Index - DTC: Head-Up Display (HUD) (G2020234) >> DTC B1A85-86: Ambient Light Sensor - Signal Invalid >> Possible Causes