Home >> Land Rover >> 2021 >> Defender 90 X >> Repair and Diagnosis (Single Page) >> Quick Lookups >> Common Specs & Procedures >> Diagnostic Trouble Code Index DTC: Body Control Module (BCM) -- Defender/L663 >> Diagnostic Trouble Code Index - DTC: Body Control Module (BCM) (G2400885) >> Description And Operation >> Body Control Module (BCM) >> DTC B124A-84: Right Daytime Running Light - Signal below allowable range >> Possible Causes