Home >> Land Rover >> 2021 >> Range Rover SVAutobiography Dynamic Blk. >> Repair and Diagnosis >> Quick Lookups >> Common Specs & Procedures >> Diagnostic Trouble Code Index: Gateway Module (GWM) -- Range Rover/L405 >> General Information >> Description And Operation >> Diagnostic Trouble Code Index: Gateway Module (GWM) (G2165407) >> DTC B1412-87: Quiescent Relay Box - Missing message >> Possible Causes